Wind energy - Wind vane

A wind vane is a simple but clever device employed to passively point something in a desired direction relative to the wind.

They work like a flag. Always trailing away from where they are fixed, being carried with the wind.

If we make a rigid flag, it's a wind vane.

If we stick something to the front edge of the wind vane, (where the flagpole is if it was still a flag) we can make that thing face the wind. So for instance if we nailed a sign to the front edge at 90 degrees, the wind would be able to read it.

Rather than a sign, we can stick a wind turbine on to face the wind.

Anything you stick out in the wind wants to act a bit like a wind vane.

Even our windmill blades.

Without the wind vane, the windmill would act like a wind vane itself and would probably loose its sense of direction.

By placing our wind vane at the end of a long pole, we gain a mechanical advantage. Leverage in this case. What that means is a little wind vane at the end of a long stick can overcome the wind's attempt to ruin everything. The little vane at the end of a long stick can stay downwind even though the big windmill wants to be downwind as well.

As long as the entire contraption can rotate freely on the pole that keeps it all up in the air, it will always point the windmill directly into the wind. If the wind changes direction, the windmill rotates and always points the turbine correctly.

I love it when people invent things that use the force they are trying to counter against itself. I realize this is a pretty simple invention, but it was still very clever of whoever thought of it in the first place.

"I wish the wind would stop blowing my windmill out of the wind. I know, I'll just use the wind to point my windmill into the wind."

That's good brain using.

So now we have a better method of making our wind turbine track the wind without having to run outside and re-point our windmills into the wind every time the wind changes direction (the Dutch were a big fan of the running outside method in their early designs). What we need now is a way to point it out of the wind when there is too much of the stuff, without having to run outside. (the Dutch did a lot of running outside to save their windmills from too much wind by furling their windmills.) (actually I think the Dutch windmill operators were live-in like a light house keeper, so they probably didn't go outside so much. They probably just adjusted everything from inside - but I'm pretty sure there was a lot of running around, and constant attention and vigilance involved)

What we need is a method of automatic furling.

Wind energy - Furling

One of the problems with windmills is the wind. Too much of it can turn a DIY windmill rapidly back into the junk from whence it came.

Wind is the enemy of the windmill. Who'd have thought it. When there is too much wind one of several things can happen depending on the application. You can generate too much electricity and over cook your batteries, you can pump too much water and all your cows get bloated or something, you can grind so much flour that you feel a bit like a magician's apprentice with all the bucket work you find yourself having to do, or the whole shebang can just blow over and come crashing down on your neighbour's chicken coop causing an unnecessary spike in insurance premiums.

"But humans have opposable thumbs, the Apollo missions, monorails, trans fats, canned cheese, and Oprah, so surely we have a solution." I hear you exclaim.

And, luckily for me, it seems we do.

The solution is furling.

Generally speaking, "furling" describes turning your windmill away from the wind when the wind gets too strong.

If my memory of my grade 4 project serves me, rather than furling their windmills, historically the Dutch used cloth sails over the wooden frames of their windmill blades. If there was a storm, the sails could be adjusted or in the worst case would just blow out and no damage would be done to the main structure of the windmill. The sails could be adjusted in varying winds to maintain a reasonably constant speed of the grinding wheel or pump.

So, short of the old Dutch option of risking partial destruction, it seems there are a few other methods of furling we might employ to automatically regulate a windmill when it's humans are absent. 

I'll cover them each in detail at some stage. Some of them are particularly clever. 

In fact, I've turned fractionally greener than my regular shade of envy as a result of learning just how clever the simple solutions that these inventors have found really are.

Wind energy - History

I often find the history of an invention or method to be very interesting reading. Not so with the history of wind energy.

The history of wind energy goes something like this....

Someone in Persia (Iran (Islamic Repiblic of Iran)) came up with the idea somewhere around 700 - 800 BCE, but we only have someone else's word for that as there is no record of it anywhere.
It's also claimed someone in Europe came up with it at roughly the same time, but there's no record of that either.
I'd put my money on Persia. They had a stack of good ideas coming out of that area at that time. But who knows. Europe was just gearing up to start burning interesting and particularly intelligent women at the stake, so perhaps the dark ages were brought on by a hundred years or so of property developers getting upset about all the windmills being built. Anyway...

Then the Dutch did a bit of work.

yada yada yada... industrial revolution...

Some farmers used them a lot to pump water, and a bit for generating electricity.

Then a semi-famous actor by the name of Ronald Reagan took some cash that was put aside for R & D on wind energy , and spent it all on ray guns in space or something. I presume that was a good idea.

Then along came the recent past, where we see wind power being a pretty mainstream way of generating lots of nice clean electricity.

This bit's interesting....
According to a recent survey, the present seems to indicate every single person* on earth is taking an intense interest in home made wind energy.

And that's pretty much it for the history of wind.

Did I mention I had a big day yesterday? I'm going back to bed.

*It's possible that there is a fair degree of error in that statistic as my sample size is quite limited, but I'm pretty sure I speak for everyone in this room when I say "Everyone here is actively involved in wind energy."

Wind energy - Betz' Law

Graphic interpretation of Betz' law
The energy in wind is a lot like the hot air in drivers. If a bit that's up the front runs out of energy and stops, all the ones at the back just plough into the back of the stopped one at the front, get angry, uncooperative, and everyone gets a lap full of coffee. Nobody's going anywhere. Wind doesn't get coffee stains - that would just be silly - but wind cant go very far when there's some uncooperative,  stationary wind up the front with no energy. So we find ourselves faced with some kind of limit.

If you take all the energy out of wind you cant get any energy out of the next bit, because in no time, the whole place is gummed up with stationary wind. So we find ourselves forced to slightly less greed, and only take a percentage.

We are forced to take less that 59%. Albert Betz did some apparently good work in finding this theoretical maximum limit for us. I say apparently, because aside from a stack of numbers and letters, his equations include things like triangles and a very great many dots where previously I thought such dots never went. In short, to me they mean nothing. Besides, my keyboard doesn't have a triangle key, so we are just going to have to take his word for it. Anyway, in reality we cant get 59% , because of all kinds of inefficiencies, and my frustrating lack of an infinitely thin rotor in my pile of junk. The best part is we really don't need 100% efficiency because there is plenty more wind where that came from, and the stuff is free.

 Hmm, perhaps Nobel simply didn't like triangles.

Wind energy - Blades

It turns out, there is a stack of energy in the wind. In fact the more I research, the more I see it that way. I'm starting to get some kind of grip on this energy stuff. I'll try to explain what I've understood so far.

Water pumping windmill
Just looking at the traditional windmill for now, (traditional to me) the one that looks like a fan, we see there are a stack of different blade shapes, and some seem to have more blades than others. Some seem to be always used for pumping water, and others seem to be always used for generating electricity. In keeping with 120 things in 20 years tradition, I'll start an explanation of wind energy by talking about cogs.

Connect two different sized gears together. Choose two cogs so that when the small one rotates 100 times, the large one rotates only once. Now give the gears some power by turning them. The same amount of power exists in the big and small gears, but in the small gear, its spread out over 100 turns. This means that you can slow it down by resting a feather on it. It has no grunt. Try the same feather trick with the large gear, and your large gear wont care a bit. 

If you put a set of wheels on the axle of the small gear you will zoom along until you get to a steep hill, or a feather.

If you put a set of wheels on the axle of the large gear, you will drive slowly through a pillow factory with ease.

Having just described this, for the first time in my life I suspect I might be leaning toward some vague understanding of "torque" that I didn't have when I started this post. I think torque might be rotational grunt, where power is what the engine has. If this is true, you can express an engine's power as more grunt or more speed while keeping the same power (the engine). That must be it. Or not. But for now, I'm sticking to "grunt", so now might be a good time to edit your dictionaries and engineering manuals.

A windmill's power comes from the wind. If the wind is fast we get more power. Now, picture a string of air 100 metres long. That's called a string of air. Now move it at 100 kph. That's called wind.

If we slice that 100 metre string of wind 100 times we get 1% of it's power in each slice.
If we slice that 100 metre string of wind 10 times we get 10% of its power in each slice.
That's simple enough.
If we have a 10 blade windmill, it makes 10 slices every time it does one revolution. That means it will make 10 revolutions as that 100 metre string of wind blows past.
If we have a 100 blade windmill, it will make 100 slices for each revolution. That means it will make one revolution as that 100 metre string of wind blows past.

The same amount of power is in that 100 metre string of wind, but we can harvest it in such a way that suits any combination of grunt and speed that we might need for our application.

The 10 blade windmill spins 10 times with stacks of speed, and the 100 blade windmill turns only once, but with more grunt.

It turns out that lifting water from a well requires lots of force, so we use windmills that have a lot of blades, and generating electricity requires a lot of speed, so we tend to use windmills with fewer blades in power generation.

A 100 metre string of air doesn't really get you 100 slices. Actually for all I know it might. But it probably doesn't. I made those numbers up to make the calculations easy to see, but it all works pretty much the way I described.

So anyway, that's the story of where babies come from.

Wind energy

There's a lot of wind about of late. It's got me thinking.

Quite a few years ago, I was talking to my two year old friend Sarah, when the subject turned to wind. I asked her where it came from. She looked at me as if I was a bit of an idiot, but then, to my delight, she patiently explained it to me.

It turns out trees make it by waving from side to side.

Obvious really.

Other than a bit of sailing experience, and a decent understanding of where the stuff comes from thanks to Sarah, I don't know much else about wind. I'm about to rectify that. I'm going to learn how to make a windmill. And then, once it's made, I'm going to do something with all that wind energy I collect. There are a few things that spring to mind that I might do with some wind power.

  • Grinding flour is one, but I tend to get someone else to pre-grind my flour. 
  • Pumping water. I do a lot of that at the moment in aquaponics, so that could be useful. 
  • Or even generating electricity. I really need to learn about the stuff, so windmills might be a good introduction to electricity. 

Whatever I end up doing with my windmill, it should be an interesting learning experience.

The weather has been too rainy and windy to put much of a dent in all the things I need to do on the new aquaponics system, so I'm reading everything I can find that has anything to do with wind energy.

Handmade fishing lures - Super lightweight lure

I found myself testing some problem solving approaches, and came up with this as a way of making a hardbody fly, or ultralight lure.

We have an introduced pest species called Redfin Perch in Australia. It's not as bad as some introduced species, but it still displaces native fish from their natural habitat. Because of this it's illegal to return them to the water, which is fine by me because they are not bad to eat.

From looking at the contents of their stomachs, I've discovered that they tend to eat very small insects that either live under water, or land on the water from time to time. At least they do here. When you catch them in waterways like the Murray river, they tend to be full of small yabbies and glass shrimp. When fish are eating tiny things, they tend to get a bit spooked when you lob great big lures into their river. I figured what I needed was a tiny, lightweight hard body lure, with a tight swimming action to look like a downed flying insect that's now swimming.

One of the heaviest components of the lures I've been making, is the wire harness. All those wire eyelets for tow points and hook hang points end up weighing more than the rest of the lure. Lightweight means the harness had to go. Also the rear hooks had to go. In fact, there was no reason to have more than a single hook rather than a pair of trebles.

I started By stripping some very thin electronics wire out of it's insulation, leaving me with a very thin tube.

Next I make a tiny lure, and thread the thin insulation tube through a hole drilled first from the front, then from the underside until it meets the first hole.

Glue bib, lure body and tube in place with a drop of superglue.

I hold it all together with Blutak while I'm gluing.

Paint it (or not), then when it's dry, trim the tube flush with the lure at the belly, and as long as needs be to get a good towpoint at the front.

Then simply thread your line directly through the front, and attach a hook where it comes out underneath.

I use them un-painted and not waterproofed in any way. I tend to lose a few to overhanging trees, and would prefer they just rust away and rot rather than hanging around for too long.
I'm using these on the River Torrens where it's only 4 or 5 metres wide at the most, so there are no issues with casting. On a windless day, I'm only just making it to the far side of the bank with a relaxed cast on 1.8 kg line. And at least 2 of those 4 or 5 metres are covered by the length of my rod and my arm. There's no casting records about to be broken with these little lures, but in the right spot at the right time, they work a treat. The redfin only measure 20 cm or so but I've seen bigger fish eat smaller things so they might be worth trying on bigger fish if casting to them isn't an issue.

The one pictured here weighs a little over one gram, and only makes a tiny splash when it hits the water. I'm sight fishing to hiding redfin, and they can be very timid or crazy brave. When they are timid, using these lures I'm able to cast a lot more often at the same spot before they get spooked. With a normal hard body lure, I might only get 2 or 3 casts before they wise up, with a spinner, that might be only 1 or 2 casts.

It might also be interesting to try them on a fly line.

[edit from the future - This post on painting lures, "how to get the most out of your printer", might interest anyone who found this post useful ]

Aquaponics - Pump-less cycling Success!

Sometimes, I know things like cycling a pile of gravel should work, but I'm still surprised when they actually do.

After shovelling 3/4 of the gravel into my grow bed, I got lazy and went to bed. But I thought I'd try getting a head start to cycling up my system as gravel in a grow bed, and a pile of gravel on the ground. 

It was about to rain, so I figured it was a good time to add some fish emulsion to the gravel. When I last wrote about pump-less cycling, I promised I'd let you know if it worked.

It worked!

My recent test showed some nitrites.

The sample pictured was taken from rain runoff, at the standpipe in my new growbed.

To make sure I wasn't getting the nitrites from the bottle of fish emulsion, I tested some fresh water with fish emulsion added. 

ammonia 2.0
nitrite 0.0
nitrate 0.0

What this means is, there were no nitrites introduced directly from the bottle of fish emulsion. What that means is that my pump-less, sump-less, no fishtanked system is cycling, because the nitrites must have come from the bacteria in my new system.

No great surprise really, but still interesting.

It's actually not that important for me to cycle my system, because I will be adding 100 litres of mature media from my test system. That 100 litres of media is currently coping with my eleven silver perch, so in the new system, it should continue to cope. As long as I transfer it in such a way as to keep it wet at all times, my nitrifying bacteria colony should find its new home welcoming. I'm told I should bury my old mature media from the small test system at about half way down into the new gravel media for best results.

Aquaponics - High density marron farm idea

I've had a few more thoughts on a high density marron farm, and they seemed to have coagulated into something that looks a little like this.

Side view - High density  marron farm idea 

The water and solid fish waste would flow from the fishtank into a flow splitter made from an 8 inch PVC pipe connected at right angles. The flow splitter would then be connected to a number of 8 inch PVC pipes that would slowly take the flow to the growbed.

Each PVC pipe would contain a number of different baskets that could move freely along the PVC pipes.

Each basket would hold one marron. The largest marron would be those closest to the fish tank, and these would get first bite at solid fish waste, and uneaten food. As the feed and solid waste moves to the right, the other, progressively smaller marron get a chance at it. Mature marron would be harvested from the end closest to the fishtank, and new small marron would be added to the system at the growbed end. Each marron would be in a separate basket to prevent fighting.

The water would enter, and move through the system via gaps at the bottom of the baskets. To maintain water in the pipes, the water would exit the pipes at the top.

Top down view - High density marron farm idea

Seen here from the top, we see the flow rate from the fish tank would be very slow because of the large diameter of all the PVC pipes. This would give the marron several chances to catch passing food. The total flow through the system is the same as it would be without the marron farm, but because it's spread over such large pipes, the flow slows.

The length of the marron farm pipes would depend on how many marron your system could support.

Using this or a similar system it should be possible to grow marron (or whatever underwater walking things are called in your part of the world), in an aquaponics system without all the cannibalism that can come with underwater walking thing farming. This marron farm would be placed in the following order of flow...

  •  fish tank
  •  marron farm
  •  swirl filter
  •  grow bed

Small marron might be kept in an aquarium, and only the largest of the batch might be added to the farm each week. Grading out only the biggest marron might prove difficult so I might have to come up with a way to trap the biggest and let the others through unhindered.

Or something.

I'm not sure if this is the solution for me. It's just an idea that was rattling around in my head, so it had to come out.

Aquaponics - Duckweed growth rate

I hadn't noticed my duckweed growing, because I tend not to notice such things. But when you compare two photos taken a week apart, it becomes difficult for even the most stubborn unobserver to ignore.

Duckweed grows really fast.

This is what it looked like on the day I bought it.

And this is what it looked like a week later. And I'd given some to the fish!

I only noticed it a few days ago when I was sorting photos.

It does grow only in two dimensions, but it is still amazing.

Duckweed is known for choking river systems, but it's only because the water is far too nutrient rich from fertilizer runoff and other intensive farming and industry. The single leaf with the insect on it still looks the same after a week. I was expecting to be able to show it dividing, but its growth is slow, probably because the water it's in isn't saturated with nutrient.

It's interesting to note the small root system the photo at the top of this post shows. I couldn't see those roots without the aid of the camera. I thought each leaf had a larger white root, but it looks like there are many on each section that will one day become a plant on its own, although its possible that those fine green roots are actually algae or some other type of bio string.

Aquaponics - Duckweed auto feeder

I've had an idea.

Duckweed grows at an amazing rate. It also seems to spread out to take up the entire surface available to it. This appears to be a function of surface tension. But I may well be wrong so don't quote me on that. In fact, don't quote me on anything.

Because of the way duckweed spreads out over it's available surface, it should be possible to use that, and various other handy attributes of the universe, to make an Aquaponics duckweed auto feeder.

Here's what the original plan looked like.

The pump for my new aquaponics system will be on a timer, and will run for around 10-15 minutes each hour. When it runs, a small amount could be diverted to the duckweed auto feeder. The diverted stream could be applied to a PVC pipe  in such a way as to divide the floating duckweed. If required, the stream could be shaped so it spreads across the width of the PVC, and perhaps points away from the standpipe. If the stream is set to spray across the top of the water, it will keep the majority of the duckweed away from the standpipe, but still allow the water to pass under the stream,through the standpipe and into the fish tank.

Here's the animation that might make it understandable.

Aquaponics - top down view of duckweed auto feeder 

  • When the water flows in from the sump pump, a small amount of duckweed is separated from the majority, so that it moves toward the standpipe (to the left) and the rest is kept away to the right.
  • The water overflows into the standpipe, into the fish tank.
  • The overflowing water takes a "dose" of duckweed with it to feed the fish.
  • The size of the dose can be determined by the placement of the water inflow. Moving the inflow further to the right would increase the duckweed dose, to left would decrease it.
  • Because the duckweed spreads out to occupy the available space, the dose would be a percentage of what remained rather than a set amount. This means you should never run out of duckweed. If there isn't very much in the system, only a small amount would be delivered.
  • The duckweed will grow faster in summer when the silver perch want more feed, and it will grow slower in winter when the fish are not so hungry. The faster it grows the more the system will deliver on each pump cycle.
  • If required, a thinner PVC pipe would allow for better fine tuning to allow a smaller amount of duckweed to be delivered each time.
Once it's set up, it should largely regulate itself.

My plan is to make a large bed of water to grow duck weed in, using goat dung for nutrient, and create a duckweed auto feeder connected to my fish tank, that I can scoop some duckweed into every few weeks.

Here's a side view animation 

Aquaponics - Split system

A rule of thumb ratio to stick to is 2 grow bed : 1 fish tank. This allows a big enough population of nitrifying bacteria to process the maximum safe population of fish.

The maximum safe limit of fish population is 3 kg for every 100 litres of water. since a litre of water weighs 1kg, we can say that 3 % of the fish tank's weight can be made up of fish. That's a lot of fish for a cubic meter of space.

The issue with the 2:1 ratio of grow bed to fish tank, is that the grow bed takes a very large percentage of the fish's water. I'd like to grow some marron as well as all these fish, so I'll want even more grow bed. Even more grow bed means my fish will be spending some of their day walking around on dry land.

Fish hate dry land.

One possible solution to this is to add some extra grow beds down at the sump level. My aquaponics space is on a flattened area of sloping ground, so its easy for me to add grow beds down the hill a bit at the sump level. This means the grow beds can act as extra sump capacity rather than being a drain on sump capacity.

When I add my marron farm, I intend to add some blue barrels as large planter pots for a few fruit trees. I'd love to grow a lime, and some blueberries, and perhaps raspberries or grapes.

My description is lacking, but luckily I spent all morning making an animation to demonstrate what I mean.

  • The pump is on a timer and runs for 10-15 minutes per hour.
  • Water is pumped from the sump up to the fish tank.
  • We make the water exit the fish tank from the centre at the bottom because with the pump creating a bit of a whirl pool, that's where all the solid fish waste will gather.
  • The water and solids from the fish tank enter the swirl filter. 
  • The swirl filter has an inlet port half way up and and outlet at the top so the solids sink to the bottom and are left behind. In the event of some kind of "over nutrient emergency", I'll be able to remove the days solids to lessen the load on the system. If all is going well, the solids in the swirls filter will be chewed up by a few cups of shell grit until they are small enough, and light enough to float out into the growbed. This should help distribute the solids, allowing them to easily flow to all areas of the growbed.
  • As soon as the growbed starts to fill, it also starts to empty via hole in the base of the standpipe, but the inflow rate is higher than the outflow rate so the growbed's water level rises.
  • Once filled, the open top of the standpipe allows water to flow free back to the lower level to prevent overflow.
  • The pump runs for a while longer. The length of time the pump runs for is determined be the need to turnover approximately one fishtank of water each hour. This helps oxygenate the water, and allows the bacteria to get a look at the ammonia, and nitrites.
  • The pump shuts off.
  • The grow bed continues to drain over the next 40 minutes or so.
  • When the grow bed is full, the planters are drained. When the planters are full, the growbed is drained. This way we introduce extra growbeds into the system without needing a larger sump.
  • Water flows freely between the planters, and the sump. 
  • When evaporation or plant use drops the water below the trigger level of the float valve, water is added from my concrete rainwater tank. My concrete tank water has no chlorine so it can be added directly. It also has a similar pH to my aquaponics system. If you use mains water, you need to have your water sit for a couple of days in the sun to turn the chlorine into something less harmful to fish. [see comments]
  • The cycle repeats.

Aquaponics - IBC's

IBC's or intermediate bulk containers are how humans shuffle bulk liquids around the world. IBC's are the container of choice when a blue barrel simply isn't big enough.

I used blue barrels in my first test system, but my new system calls for recycling on a far grander scale.

I finally managed to organize 2 IBC's, a car with a towbar, and a trailer, all on the same day, at the same time.

I also organized for it to be a spectacular day.

My IBC's originally had honey in them. They are clean, made of food grade plastic, and a little bigger than a lot of other IBC's I've seen.

Interestingly, they also have a heater in them. It turns out it's not at all uncommon for IBC's to have heaters to allow stuff like honey to flow on cold days. It seems amazing to me that we make single use containers with a plug hanging out of them. The few hours I spent in the back alleys of our port district was a bit of an eye opener in terms of just how much waste there is in industry and transport.

The "food metres" involved with aquaponics coupled with some recycling will ease my troubled head a bit.

But not much.

One IBC will be used as a fish tank and the other as a sump in my new CHIFT PIST aquaponics system.

Aquaponics - Duckweed


I finally got hold of some. I've been looking around for it for ages, but all the plant stores stock a plant that isn't really duckweed. Every single nursery I've been to has assured me over the phone that they stock the real deal, but have all turned out to have something else.

I guess I should mention that the reason I wanted the stuff is because fish eat it. Its a great way to get rid of excess nutrient, and is also a useful feed because it floats so doesn't get sucked into the pump before the fish get a chance to eat it.

It looks like this. At least I hope it does. All plants look the same to me.

Duckweed has some claim to fame. I'm told it produces the smallest flower. But I wasn't told it makes three of them, so I guess there is good reason to doubt it's record holding status as well.

Who knows.

I have duckweed.

As far as I can tell duckweed normally reproduces asexually by dividing into two leaves. If you look at the picture, you can see some leaves almost look ready to divide. Many of the leaves have two roots extending ten or fifteen millimetres into the water. I'm guessing when the leaf decides into two, each half gets a root. I'm told that it also does the pollination thing from time to time, but who knows.

I have duckweed!

I put some into a large container with some fish emulsion as fertilizer. After a day or two I noticed an oil slick, so I  added an air stone attached to a small fish tank air pump. The slick cleared up within a few hours, and the duckweed took on a healthier shade of bright green. I know there isn't a lot of science in that, but I'm guessing duckweed needs oxygenated water. I was hoping to just keep it in a container of water with a large surface area, throw in some goat dung, and leave it to it's own devices, but I don't think it's going to be as simple as that.

The plan is to use the original planned growbed with pvc edge capping for a duckweed plantation. The growbed was too easily scratched to use with gravel in it, but filled with only water and duckweed, it should be fine.

I kept it for five days before giving it to them because I was concerned the pond it came from could have had some diseased or parasite infested fish.

I only know a small amount about one fish ailment other than poison plants, and that is a parasite called Ich. Ich is a fish parasite that can't live away from fish for more than three days, so at least my five days should prevent it from being an issue.

Aquaponics - Pump-less cycling

Fish-less cycling is where you breed up a colony of nitrifying bacteria in your aquaponics grow beds by adding a source of ammonia to your water as it pumps through your system. You do this because there is some risk to the fish in an immature system. Those risks are lessoned once your system is able to turn ammonia into nitrites, and then nitrates, at a rate that will allow the system to cope with the desired level of fish stocking density.

I still don't have my fish tank and sump, so I thought I might give the nitrifying bacteria a head start by just adding hardware store bought fish emulsion by sprinkling it on with a watering can.

I still don't have a watering can so I made one from an empty soft drink bottle.

I have no idea if this will work, but once I get my fish tank and sump, I should know if it has helped speed up the process of cycling the system.

Its about to rain so I'll just sprinkle it on top and let the rain do the rest.

This is the second time I have done this, and the last time the gravel remained wet for a week, so there is a chance this might work.

I'll let you know.

Animation - Bell siphon

I've decided to learn how to make animations so as to be better at communication.... And stuff.

Earlier attempts I have made were created frame by frame, but I recently nabbed a copy of Synfig Studio.

From what I've seen so far, It looks the goods. Its free to download and use and its all open source. Yet again the open source community has exceeded my expectations. All these people who contribute are truly amazing. Thank you all.

Here is my first attempt that actually worked. Depending on what I can offer, I might make animation or visual communication a "thing" because I'm sure I'll need the skills more and more, no matter what I do in the future.

The bell siphon is running with a continuous inflow of water. The siphon triggers when the standpipe fills with water. The grow bed (terracotta colour) floods and drains automatically, creating tide-like conditions for plants. The bell siphon is commonly used in aquaponics as a method to flood and drain grow beds. The water drains back into a fish tank, where a pump cycles it back to the grow bed.

A bell siphon (in yellow) triggering and draining via the standpipe (in green)

The real things looks like this from an earlier post called "Aquaponics - Glass bell siphon"

I just re-read this post and it doesn't sound like me.
But it is.
There, that's settled that.

Aquaponics - Goats really are fun

My goat broke my automatic feeder today.

I guess it tasted good, but it might have been more polite to just eat the fish feed and leave the switch alone.

And so far the only gold I have found in all that gravel was this.

It's an interesting crystalline substance that, up close,  looks like plastic gold jewellery, mixed with crushed glass.

I've never seen fools gold before.

I don't feel foolish.

Other than that, everything at the auction I went to was selling for way too much so I'll forget buying a purpose built fish tank, and go back to the original plan of buying some IBC's.

IBC's are how we humans move our ever growing numbers of litres of liquids needing transport across the world. They are generally white(ish) plastic and take the form of a cubic metre drum in a cage on a pallet.

Make sure you know what was in them before you buy them. There is a stack of toxic stuff moving around the globe in these things on any given day. Luckily, many of them carry things like soft drink syrup. Many are not food grade plastic, and its a good idea to check for cracks and flexibility as they become brittle after too long in the sun.

Aquaponics - Marron stocking density

I'd like to grow some marron but they eat each other.

One of the issues with things that use their claws to catch and kill things, is they tend to use them on each other, or their young.

Marron, for those who don't know fall into the "things with claws that walk on the ground under water" category. They also fall into the "delicious" category.

The problem is that, because they eat each other, you cant keep many in an aquaponics system. Given a choice, marron would like to be left alone and hangout and eat. The problems arise when they go looking for food, or a mate, or when the just go out for a stroll and bump into another marron also out for a stroll.

One solution is to give them plenty of hides in the form of hundreds of short lengths of PVC tubing. Which sounds like a good idea because I seem to love using PVC tubing, but I'm not sure if it solves the bumping into each other problem.

Another is to only populate one marron in each half square metre of fish tank bottom space. That would only allow 2 or 3 in a 1000 litre system, but allows each marron to back away from more aggressive marron they meet strolling around. I'm hoping for stocking densities that might allow 30 or 40 marron in my new fish tank rather than 2 or 3.

Yet another solution I have seen, was to create high rise housing that float around in a fish tank where each crustacean (yabby in this case) has its own space to stop them killing each other.  The yabby spaces where stacked on top of each other so that in a one metre deep fish tank, there might have been ten stacked on each other. These yabby buildings floated around in the current. The problem I see with this approach is that unless there is a great deal of turbulence in the water, the feed might never meet the yabbies. In the system I have seen video of, there seemed to be a great deal of wasted food that simply got filtered out of the system, and dumped.

Other than the feed issue, the marron high rise seems like the best idea. I think I'm leaning in that direction, but perhaps with a way of feeding each "building" via a tube that runs down through each marron's house, so that each marron gets a share of the food, and nobody misses out.

I'm off to buy a fish tank or two tomorrow, so I want to design a system that includes marron before I start building my new bigger aquaponics system.

My research continues.

Aquaponics - Goat

As useful as Granger was in helping me to make home made goat dung volcanic growing media, it turns out goats have no place near plants and gardens.

I thought I had him safely blocked from my small aquaponics test system, but people often think things like that when it comes to goats, and are often proven wrong.

This is what my grow bed looked like before the attack (actually this picture is older but you get the idea).

And this is the same plants now.

I walked into the back yard and saw my goat chewing a mouthful of strawberry plant, with an expression of surprise that I seemed to be upset.

I replied by turning on the hose, running around shouting, and trying to squirt him.

He seemed to think it was all great fun and promptly did what goats do when you chase them around squirting them with a hose. Head for the hills.

That's him on my roof.

Laughing at me.

My grow bed looks like this now.

I managed to save the rosemary, two strawberry plants (one with two runners forming), and some celery.

Aquaponics - Gravel


I got some 20mm blue metal road gravel, as growing media for my new, larger aquaponics grow bed.

It looks like this.

And unfortunately it needs washing.

Also unfortunately, there is three tons of the stuff.

Actually it's not necessary to be too fussy when washing gravel as the system takes care of a lot of it, but this seems like very dirty gravel so it needs a good rinse at the very least. It's one of those things that takes so much work to redo if you don't do it right the first time, that its worth putting in the effort the first time.

I was hoping the truck might be able to deliver the gravel directly into the grow bed, where I could then rinse it with a high pressure hose. Unfortunately the grow bed was a bit too high for that, so it had to be unloaded in a pile next to it.

Its actually a good thing it wasn't able to be be dumped directly into the grow bed, because it had much more dust on it than I had anticipated.

Washing gravel is hard work with all but one method. Some bright person came up with the idea of just washing it with a fire hose when its in your trailer, or truck. By all accounts this seems to work well, so if you have that option, it's probably worth trying.

Its been a few years since I shovelled 10 ton of stuff from one spot to another, and in those few years, stuff has got a whole lot heavier.  Even when it only weighs 3 ton.

Unfortunately it didn't quite all get done.


Aquaponics - Media screen and standpipe

To try to keep all my gravel from grinding into the pump in my new system, I'm going to need a large media screen.

The media screen's task is to prevent any gravel from flowing out with the water. The easiest way to make one is to make it out of PVC. PVC is turning out to be my favourite material to use for all kinds of things during my time spent so far learning 120 things in 20 years.

The screen needs to be big enough to put my arm into in case I need to adjust something, or remove a snail or something. The PVC I'll be using is around 200 mm in diametre.

I cut a length at 400 mm because the plan is to make the gravel 300 mm deep, and to prevent gravel falling in when I'm digging around, it needs to be around 100 mm above the gravel.

I concentrated all the holes at the bottom, because if this device doesn't work well at the end of the cycle, when the tide is low, it wont work. Any holes at the top are not really needed if there are enough holes at the bottom.

Then Cleaned it up with a small hand held rotary tool. Any wire brush would do, or you can use a file, or even a drill bit a few sizes larger. If you use the bigger drill bit method you can just twirl it around at each hole even by hand. You also get very nice bevelled edges and it's quicker, but I didn't have a bigger drill bit.

The next task is to place it in my new grow bed, and fill the grow bed with gravel.

Aquaponics - Beasties

I found some alien beasties in my new grow bed.

It's not often that you get to mark out three square metres or so of clean wet stuff on a high contrast background, and see what moves in overnight. In the morning, there were some bug deaths, some bugs just getting on with their lives, and my first bug births. I have no idea what they are, but they only took 12 hours to move into my new grow bed. 

Very very small beasties

I put a few hundred litres of water into the grow bed to test my silicone, and to weigh it down.

I'm hoping the truck that delivers my gravel will be able to dump it directly into the grow bed saving me a stack of time. It wont be able to, but it keeps me from thinking about having to shovel gravel.

It's no wonder people buy bulldozers.

Aquaponics - Fish waste solids masticator

I guess it's just plain laziness, but I'd rather not chew my fish's solid waste.

Luckily shell grit is willing to do it for me.

This is as yet untested, and in my experiments so far, there are some potential stumbling blocks to overcome, but this is what I'm working on...

We need shell grit in the system to buffer pH, so I figured I'd put it to use to break down solid fish waste, before it enters the grow bed. This is probably unnecessary, but I'm hoping to distribute the waste more evenly throughout the grow bed. I'm also hoping to grow some strawberries in PVC pipes at some stage, so it will be necessary to have very clear water running through them so they don't block, as the roots will almost fill the pipes.

This represents a possible solution to keeping the water moving freely throughout my system, if I end up needing it.

The general idea is that fish solids enter with the water, and because of the direction of the inlet flow, they swirl around. The water overflows leaving the solids behind. In aquaculture, and sometimes in very densely populated aquaponics systems, this is employed with a tap at the bottom to allow removal of the solids from time to time.. It's called a swirl filter or solids filter. All I'm thinking about doing is adding shell grit to one, and making the grit and the solids tumble around until the solids get small enough that they rise up and overflow in the grow bed with the water. I don't want to lose my solid waste because me plants want all the nutrition that's in it. The general idea is that it should be a prefilter, and double as a way to add calcium carbonate.

In my larger system, I think I will incorporate a solids remover in case something goes wrong and I need to instantly lessen the nutrient load. I wont need to empty it in normal use, but I will have the option in an emergency.

Aquaponics - String feed counter

The small volume of the food that's being dumped each time my on demand feeder triggers makes it difficult to measure, so I've been trying to figure a way to register trigger events.

My fist attempt at measuring the times when my fish triggered the feeder was a small spot of blutack on the top of the shaft. If the shaft moved while I was away, I could tell. But it turned out that the shaft turned one full revolution on at least one occasion, so there was no way of know if the fish had triggered it or not because the blutak was right back to where it started.

The next was a small pebble that I could leave sitting on the top of the shaft. If triggered, I would find the pebble lying next to the shaft. This worked but could only measure one trigger event before I would need to notice it, and reset it.

My latest design is a piece of string attached to the shaft, with a nut on the end for a weight. When the fish trigger the demand feeder, the string winds around the shaft, and raises the nut up.

It wont tell me exactly how many times it was triggered, but will give an indication of how long the motor ran in the time since I last reset it. Each time the fish hit it, it seems to turn approximately one revolution, so I should be able to mark off a rough guide on the wood. This should make a reasonable gauge to tell me how active the fish have been in setting off the feeder.

Aquaponics - Demand fish feeder success

I think I can safely say my fish feed themselves now.

Its been only five days since the fish first set eyes on my on demand feeder, and in the last 12 hours they have triggered it around eight or nine times.

They seem quite casual about using it now. Although The smallest of the fish in the tank just lurks near the lever, looking up at it. This little guy spends almost all his time looking at the lever, waiting for someone else to press it.

Water tests are showing no ill effects from the new feeding method, although I wouldn't expect them to. Feeding gradually all day rather than in large lumps a few times a day, should see the ammonia load maintain a nice steady level. A stable ammonia level, in my case zero ppm, should allow for the bacteria to maintain a relatively stable population. As far as I can see it should make the system a little more forgiving, and generally more stable.

Another advantage is that there should be less wasted food. With my regular method of hand feeding, I fed the fish until they stopped eating the feed. This meant that every time I fed them, a small amount would be left uneaten, to sit on the bottom. This represents no great loss because uneaten food all turns to plant food in the end anyway, but the plant food may as well go through a fish before being eaten by the plants.

My next step will probably be, to add a hopper to feed the auger. This will only need to be something like an empty soft drink bottle upside down over the PVC chute. While I'm at it, it would be a good idea to weather proof and possum proof the entire device.

All in all this experiment has turned out to be a complete success.

The cost for the motor and gearbox was around AU$20. I used a short length of flexible plastic tube to connect the gearbox shaft to the auger, which I already owned.

Aquaponics - Slugs 2

In keeping with my policy of being wrong from time to time, it doesn't seem to be slugs eating my strawberries.

The night before last it was raining, and the slugs were out in force on the paths around the small aquaponics test system, so if ever there was a night for my trap to work, it should have been this one.

My beer trap managed to trap exactly no slugs whatsoever.

It did however manage to catch a number of very small flies. I doubt they could have been the culprits, but the fact that they like beer may indicate they like fruit. Often bugs seem to be attracted to the ethanol produced in decaying fruit.

My strawberries where in good  health, and not at all over ripe, so who knows.

I might try flooding my garden bed to see what crawls out.

Aquaponics - On demand fish feeder

A while ago I tried to make a fish fed fish feeder design that would allow the fish to feed themselves.

I think It's made.

I say "think" because the fish have only triggered it twice in its first 12 hours of it being set up in their tank, and it's too early to tell if it works.

I bought a small 12 volt electric motor and gearbox, and connected it to an old drill bit from a hand cranked wood drill.

I cut a section of PVC pipe lengthways as a feed hopper, and filled it with feed.

The gearbox on the motor means the output shaft spins at only 36 revolutions per minute, and is quite powerful.

The next step was to find a switch that was very delicate to operate, so the fish could just lightly touch it to activate the motor.

I found a suitable lever switch, and glued on a plastic knife to extend the lever down into the water.

Now if the fish touch the lever, the motor engages, rotating the drill bit, forcing a small amount of feed along the PVC hopper into the fish tank.

I added a key, and a clip from my office as additional weight to set the trigger closer to being activated so the the fish need not hit the lever so hard.

It does actually seem to work, and the fish have set it off twice so far.

Only time will tell if it will really work as a feeder, or if every now and again, a fish just bumps into it and never associates the drop of food with the press of the lever.

[Note from the future - there is a LOT more to this project in later posts, including a new digital version where you can set the total amount of feed from a pinch to a bucket, and a stack of other features including a dawn reset so the fish can live on natural time rather than Greenwich imposed human time - there is also a video of the fish feeding themselves, and here is the results of a search on this blog for fish feeder for a stack more information]

Aquaponics - Finished the new grow bed.

It took a few weeks, but I've finally finished the new grow bed.

It still doesn't have a fish tank, a sump, or any plumbing, but it should be ready for some gravel.

If I get gravel, I can start to grow some nitrifying bacteria. Then I'll be well on the way to a decent system.

I glubbed on a stack of silicone.

Weighted it down with everything heavy I could lay my hands on.

Until I saw a bead of silicone telling me it had covered the surfaces nicely.

Cleaned it up, and its done!

This grow bed has taken way too long to get finished. Especially given there wasn't really anything that needed to be done. It should have taken an afternoon rather then the weeks it has.

Aquaponics - Slugs

As much as I wanted to eat my first strawberry, it turns out something else wanted to eat it more.

I like slugs as much as the next guy, but now I like slugs as much as the next guy if the next guy has just lost his first strawberries to slugs the day before he was going to eat them.

If the neighbourhood slugs are willing to share their half eaten strawberries with the me, its only natural that I should be willing to offer them a small spill of my beer. So I will.

A beer snail and slug trap consists of a small bowl of beer. That's all it takes to draw all the slugs from my nice organic produce into the depths of depravity, and drunken stupor.

Unlike the thirty or fourty years it might take my fellow humans to die from over indulgence, slugs achieve this feat within hours. Or so I'm told.

I can wait all night.

Is there anything beer cant do?

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