Aquaponics - Evolution and filtration

I get the feeling that stuff sticks in an evolutionary kind of way.

For a while I ran my water to the grow bed directly into my media guard around my siphon. Someone thought I might be bored and playing around too much and thought it might be a risk to the fish, so I stopped doing it.

No doubt sound advice.

But I suspect it worked fine, because any solids that didnt stick, become free to move around giving them another chance to stick somewhere else.

I found the water was still crystal clear, in spite of returning some water back to the fish tank without having put it through the media.

I also find that my scoria grow bed manages to filter out it's own dust within a few minutes these days. If I dig the bed over like I did when searching for worms, the water gets a bit clouded for only a very short while. The particles floating around in the water always find a place to settle down, even when they are tiny.

For some reason it hadn't occurred to me that it's because of all the chances they get.

It's inevitable that they get stuck.

They only have to get stuck once.

Thinking - The Invention Engine

These last few weeks have found me often running the same question through the invention engine to see if I can contribute in some way to getting the power requirements of an aquaponics system down low enough that it becomes viable to run from a solar panel, or at least to try to make it cost as little atmospheric carbon as possible.

I just keep running the same question through the invention engine with the new parameters. ie "NOT all the stuff that's been thought of before".

I remember reading about some design software that made TV antennae that I think were built into the TVs and were created using a printed circuit board that had a zillion lines that related to harmonics of the frequencies (or something - it may have been a dream - and if so, I just had an idea) But the result was you couldn't patent the design, or rather there was no point, because there were a zillion combinations of lines that would work just as well or better than the first one the design software would spit out.

All the opposition would have to do is run similar software with an additional "NOT that one those other people made" bit of code and they would have a brand new invention that worked just as well but was very different.

The people who made the software would use it to solve problems (like the travelling sales[person] problem for people.

The travelling salesman problem has been around for a long time, and there are a lot of different approaches to solving it. This made me very aware of the "NOT that one approach".

Often I'll come up with a solution, just for a plumbing problem or something, and run the problem again with the "NOT that last solution" added into the thinking process, just in case there is another option.

So far, every single time I've tried it, there has always been more than one solution to even complicated ideas and inventions.

It makes me want to put the invention engine through itself with the "NOT that one clause" added.

That should be it's final test. The downside being that I might have to start testing again from scratch.

120 Things in 20 years is now a place where I'm thinking you may soon see me get stuck in an endless loop of testing the invention engine process by re-inventing the invention engine with the invention engine, then re-inventing that with the new invention engine. Forever.

Electronics - Solar panel

I bought a stinking great big solar panel at auction online. A real life auction, in a local auction house, but I bid online.

When I went to collect it, the glass was broken into a zillion bits. I counted them. One zillion exactly.

So I offered them $50 for the two that were left and they thought that seemed reasonable.

I only brought one home because the person who had bought the other one needed to have to option to take it, but the one I do have looks like this...

It's big.

It also gloops out 230 watts of whatever watts are.

Which is nice.

If I can find a slice of glass to cover it, it may even prove useful.

I have big plans for it.

I'll use it to power my aquaponics system for one thing, but I have bigger plans for it.

I'm going to use it as a shelter.

If it still works.

120 things in 20 years, where you may well find electronics, and solar panels, but your just as likely to find nothing.

I've been too busy to post stuff, and it's about to get worse.

Aquaponics - Thinking low energy

Just for a laugh, I thought I'd run the low energy aquaponics question through the invention engine yet again.

Yet again, it spat out something surprising.

So far we've seen it cough up a zero head system, and then try to raise and lower a grow bed by pumping air under it, then releasing it. We've seen some kind of wacky stepped air lift, and a device that dumps air from a small pump all at once to make it pretend to be a big pump, but only for a brief moment. That way, we might send a big lump of air acting as a piston to carry water up a pipe. (I think I might have missed one) That last one I think has some potential, and might also apply to this next one. But this most recent one is most interesting, and it's this...

If you put air into a media filled grow bed that's also full of water, the air should displace water. If the grow bed is attached to a fish tank so that the water can breath in and out depending on the amount of air flow, we should see something a bit like a zero head flood and drain system, running on a few second burst from a decent sized air pump, once every 20 minutes or so.

You would need to turn the air on and off so the grow bed breathed in and out and changed the tide.

Easily enough done.

With a big air pump only running for a few seconds every 20 minutes or so, we might see a turnover of fish tank water comparable with a standard system.

So we put a stack of air stones into a grow bed under the gravel.

We flood the grow bed constantly, and connect it to a fish tank so water can move freely between the two.

Each time the air is turned on for a few seconds, water is displace by the air, and the water level of the grow bed rises.

The water then overflows into the fish tank.

The air stops, and the water fish tank water flows back until the two are back to the same level.

Repeat as required to turn over the fish tank water every hour.


Aquaponics - Another build error

I forgot to put a standpipe in the new grow bed.

This means the water depth is only 10 cm instead of 27cm.

This also means those plants I planted are all dead.

Still, I think 4 errors in all that isn't too bad.

And all of them easy to fix. I've already made a temporary fix and the system is running.

Aquaponics - System build

I made a bit of an improvement to my aquaponics system.

It went like this...

I started with one of these.

It's commonly called an IBC or International Bulk Container/Carrier.

They are used to freight liquid stuff all over the world, and there are a lot of them.

If you don't normally, wander down to your local dockyard or industrial/freight area, and you will be particularly amazed by two main things. First that we realy burn a lot of fuel in a lot of trucks, ship, planes,  and trains, and second, we use a lot of containers to move all the stuff that we burn all the fuel for.

Many containers are used only once.

Mine brought honey from somewhere, and even has a heating element under it.

I bought them ages ago in a previous life on a farm.

It's a strange and disturbing thing to discover that we humans make single use containers with mains power cords protruding from them.

It's a little bit wrong me thinks.

But anyway, reusing one for an aquaponics system has got to be a good thing, and a lot of people have done so.

That thing leaning against it is my SLO or solids lifting overflow. Or at least that's what it will look like when I make it.

The point of it is to move the solid fish waste from the fish tank(where the fish don't want it any more because it smells and tastes bad), to the grow beds (where the plants would quite like it). A SLO is another thing that a lot of people have used.

A lot of people are very clever.

I know some of them.

I even call some of them friends.

I'm friends with clever people.

Which is nice.


the plan was to squeeze a one and a bit cubic metre fish tank into a 1.8 cubic metre grow house, and still have a stack of room left over for growing stuff.

In fact the ultimate goal was to squeeze a one and a bit cubic meter fish tank into a 1.8 cubic metre grow house, and still have 1.8 cubic metres of space left over to grow stuff in.


But by bending space and using a roof for a wall, I nearly managed it.

All I need now is something to wrap the bottom of the new fish tank in and nobody will be the wiser.

I think it looks better than the original, but that could be a dehydration issue.

It's really hot.

Or at least it's really hot in a growhouse when you are trying to fit big things into small spaces.

One of the problems with using a honey freighting container is that it's difficult to get the honey out.

That's why you need a heater.

Heat makes honey runny.

Heat makes fish runny as well, but it doesn't taste so good afterwards.

So to make it so I could get the fish in and out, I drew a rectangle.

The best thing about drawing rectangles is that, once done, you can use the drawing as a guide to get a power saw involved.

But the close cousin to the power saw is the hole saw.

I cut a hole as a thing to put your thumb in to act as a handle.

This rectangle is going to be a door soon.

I also drilled another hole along the line so I could put a jigsaw blade in to start the cut.

And then a few more holes to allow me to tie some fishing net mending line through to form a hinge.

See the tape and stainless steel wire holding the entire thing together.

I did that.

It nearly cuts straight!


I've had this jigsaw for longer than anything really long.

And it still works.

But it's really loud, and shakes a lot.

Some would say the bearings are shot, but I say the name says it all.

It's meant to jig, and jig it does.

After a few hours of jigging, it started to look like this.

It turns out IBCs are made of slightly sterner stuff than I first thought.

Not much sterner, but slightly.

The plastic is thicker than I thought, and less brittle.

It needed a little support to keep the jig saw from creating a friction fire, but it was easily dealt with by the addition of a trusty stick.

I choose a milled quarter round stick.

After what seemed like hours, the hatch was finally cut.

I suspect it seemed like hours because it actually was hours.

Apparently, after 20 years or so of frequent use, it seems it's best practice to buy a new blade.

Who knew.

Luckily, as mentioned previously, I strive for second best practice.

Here's a photo that doesn't really contribute in any way.

Oh hang on, yes it does.

It shows the newly revealed inside of the fish tank with the hatch sitting on the top.

A 30 second scrape with a file smoothed all the rough edges.

One of the best things about working with plastics is how well all your tools work.

Even sand paper is satisfyingly productive to use.

I found myself walking on the leftover cut outs from months ago when I cut the NFT holes, so thought I'd use one as a latch to stop the lid from falling though into the fish tank when I close it.


Now it looks like this when the lid is closed.

The point of the lid, is partly to give me some control over evaporation, but mainly so that I dont need to fish about with a net all day whenever I decide to foolishly use the top of the IBC as a work bench.

When I try to use the top of the IBC to put stuff on, the lid will force me to close it in order to get to the nice flat space behind it. The lid sits at 90 degrees, when open, because it rests against the frame of the grow house.

That's the frame just under the brand name.

The 90mm PVC pipe with the elbows on each end are to gently introduce the grow house fabric to it's new shape.

I used cable ties to connect the PVC directly to the IBC frame.

That should give a ton of security to the growhouse in windy weather.

It took an hour and twenty minutes to fill from the tap, and looks really inviting.

Which is lucky, because the first of my errors was to fail to put any kind of screen over the outlet at the bottom.

The result is that I might need to go for a swim.

The next step involved not going to the hardware and plumbing stores any more to return, and re-buy everything.

Luckily I found this solution to deal with the transition between PVC and black poly pipe.

I tried all kinds of arrangements and only reluctantly remembered from my earlier solar hot water heater experiments that silicone doesn't stick to poly pipe.

These saved the day.

They didn't actually fit the rest of the design or anything convenient like that, so I needed to file them down a bit.

And then had to file down the PVC linkage.

Until the adaptor nearly fit inside the PVC

And then had to bash it with the flat side of a hammer.

But then it fit perfectly.

Then I had to trim it.

So it would fit into my 50mm PVC "T" junctions without taking up too much of distance between the fish tank, and the rear wall. I needed to add three taps so I could control the distribution of water throughout the system.

The taps will be 25mm poly taps, and that's the point of this PVC to poly adapter.


The plan is to send some water to the original grow bed with one tap, to the two new constant flood grow beds with the second tap, and to the half inside, half outside tomato/mellon/pumpkin grow bed/duckweed tank with the last tap.

I included a bit of space so if needs be I could add another tap down the line by splicing it between the fish tank and the first tap.

It looks like this inside.

I tried to minimise the potential traps where solid fish waste might collect.

Each join has silicone jammed in all over the place.

I'm told the blue glue that you normally use on PVC plumbing is a better option, because you can unstick your work with the application of a bit of heat.

I went with the ever confident silicone.

I'm all about commitment.

I stuck a stack more on the outside as well.

I really don't want to have any more leaks.

Fish hate leaks.

The final product looked like this.

Next up was to deal with the internals of the new grow bed.

I used a lot of silicone.

This is another transition point between whatever the blue barrel lid plastic is, and poly pipe.

Poly pipe doesn't like silicone, but there was an existing screw thread in the lid that only needed puncturing, and a poly pipe screw thread 25mm elbow fitting fit perfectly. I siliconed it a lot anyway.

And then did the same to the outside.

And then plumbed the barrel back to the old fish tank, now the sump.

Next up was to create a media screen so the clay ball growing media in the grow bed doesn't try to escape into the plumbing.

After sawing and filing and sawing and sanding and bracing the half cut screen with a crazy arrangement of clamps, I discovered you can just cut 90mm PVC storm water pipe with scissors.

There's a hot tip.


Then I drilled some holes in the media screen to let the water through, but keep the media out.

Round holes.

To keep the clay balls out but let the water through.

Round balls.

And then placed the media screen over the drain hole, and started excitedly adding the clay balls.

A few fell through, but that was to be expected.

But for some reason, I didn't expect the round balls to sit in the round holes.

And block those holes.


Oh well that was error three.

Error three appeared just before error two, but I wasn't aware of error two at this stage.

So I made this.

I made it out of something that looked almost identical to this before I started.

Only slightly longer.

Originally this was some back room shelving from a now defunct Adelaide department store called John Martin's. I got a very large quantity of it at auction for free.

Which is odd.

The upright brace of the old shelving, coupled with two laundry baskets made a reasonable roost for half the new grow space.

The other half is yet to be made.

I also have a tip.

If you want to really crank up the pressure on your ratchet clamps that seal your poly pipe to your poly elbows, you can squeeze with everything you've got...

but if you are as feeble as me, you can use the handles of a pair of pliers to get that one last click out of them.

My pliers failed to be just quite large enough to get their jaws around the clips used for 25mm poly.

But the handles worked a treat.

And the final result looked like this.

The wire you can see is one of two stainless steel wires I wrapped around the grow bed to stop it spreading.

And error number two was brought to light at 4am when I sat upright in bed and realised that ever after planing for just the right angle that the taps should depart the SLO to maintain an equal distribution of water to all three taps, for some crazy reason at the last minute, just after applying silicon, and just before going to bed, I thought I'd forget the plan, and tilt the tap "T" junctions down at an angle that would mean all the water would be biased toward the first tap.

The original plan called for this.

Almost, but not quite flat.

Not quite, so fish solids wouldn't get trapped, but almost, so all taps would see similar flow.

But for some reason I made this.

This would mean that I'd need to close the first tap right down, and make the path through it a perfect trap for fish solids.

I think.

So at 4am, I suddenly sat up and ran outside to twist everything back into the correct angles.

The silicone seemed forgiving at the time, but only time will tell.

It shouldn't be an issue, because there's no pressure involved. If it leaks, I can just seal it from the outside with yet more silicone, but I think there is some kind of lesson to be learned about plans, and sticking to them.

I still don't know what that lesson might be, but I'm pretty sure it's there somewhere.

120 things in 20 years, where sometimes you can make a stack more room in your brain by posting all the accumulated stuff to do with an Aquaponics - System build

Aquaponics - The daze just keep slipping by

The daze just keep slipping by, and my system doesn't look like its any closer to being finished. Sometimes I wonder what it is that takes up all the other hours.

After buying and returning all the plumbing bits 3 times each from 2 different stores, the one advantage is that I'm now on a first name basis with some excellent plumbing supply people.

The unfortunate , and perhaps inevitable disadvantage, is that they no longer like me very much.

120 Things in 20 years, where sometimes the fact that a word like "days", sounds a bit like "daze", is reason enough to post something about aquaponics, and the way things can slip by.

Aquaponics - Species deception

Sometimes animals and plants look like other animals and plants.

I like the ones that do.

I've even grown some.

These two varieties of capsicums are the same species according to the seed packet, but clearly one of the plants is pretending to be someone else.

It's nice to see there's still a chance of randomness even if it's only through error.

I get the feeling all the chance has been taken out of seed production by cloning.

To be honest, I'm a little surprised I even noticed. I've been flat out trying to build my system expansion with what little free time I find myself in control of.

Hopefully by tomorrow, I'll have something to post about my new system.

Thinking - MIT

I signed up for a course at MIT.

It mentioned ...

"students are encouraged to have the knowledge obtained from a college-level physics course in electricity and magnetism (or from an advanced secondary-education course in electricity and magnetism, as with an Advanced Placement course in the United States). Students must know basic calculus and linear algebra, and have some basic background in differential equations."

...which rules me out completely as I don't actually know what those things mean, so I'm not really expecting to finish it, but I'm always keen to learn.

My plan is to fake it, and see if I can learn a stack of stuff along the way. If it works, I'll have a new methodology in my bag of "how to get to understand stuff" tricks.

If it doesn't work, I'll have a story to tell.

Regardless of it working or not, I'll be spending some time hanging out with some people who do know what that stuff means, and that can only be a good thing.

Also it will mean I'm leaving my comfort zone in a very big way, and that has to be a good thing.

Doesn't it?

Clearly I haven't thought this through.


Everything will work out just fine.

It always does.

I believe it was Yoda, or Buddha, or someone who once said " Hmm, that looks interesting. I think I'll take it."

The fundamental differences between important social humans, and monkeys who like shiny things escapes me, but that might be why I keep trying to learn everything.

120 Things in 20 years, where everybody is always never confused about thinking about MIT.

What, me worry?

Aquaponics - Building a better air lift

Just because I've never seen my blog being poked with a pencil on youtube before, I thought I'd reply to this via a post...

This is a comment by Mike Creuzer on my post about a new air lift design I'd been thinking about. It looked like this...

The water level will be the same in the air-stone line as it is in the upper pocket. Air won't try to go up the tube until it reaches the bottom of it. (that's a lousy sentence, isn't it?)

How about a video? I like videos. Take a look at and see if I explained my thoughts clearly enough (probably not)

That's a good point.

I think if the secondary tubes were removed, the water level will be pushed down by the accumulating air pressure in the chamber. and eventually underflow* in to the next air lift all by itself.

But now, after hearing Mike describe what's happening, I'm a little troubled by the way the air is expected to  travel down into the chambers. I think this means that the operation will be stop start. (which might be ok - see the future)

This post from BYAP forum from me might explain it better...

Post subject: Re: Low Energy Aquaponics - LEAP Posted: Tue Feb 14, 2012 2:57 pm...

That wasn't so much as a design, but rather a vague notion. If I was playing with it, I'd probably start with making each step overlap by around 75%. ie in an IBC with each step being 100cm, I'd make the first lift from ground level to water level, the next from 25 cm off the bottom of the IBC to 25 cm higher than the water, the next from half way up the IBC to 50cm above the water... that kind of thing. But instead of 25cm, I'd use whatever height the first step could lift a decent amount of water to, above water level.

Then if I could raise more water higher than the a single straight air lift, it could be considered a worthwhile thing to have learnt. If I couldn't, I'd consider it a worthwhile thing to have learnt. 

But it all depends on exactly why it is that the lift works. If the air is just acting like a piston and pushing water up, then I doubt it will work. But it the air water combo is floating on the surrounding water because it displaces more than it weighs, then it might. Actually, either way it might.

Or not.

But, only a 5 minute test with a length of poly pipe, 3 elbows, 2 air stones an air pump, a 1L jug and a stopwatch will tell.

If I don't know the physics behind something, but have a vague notion, I knock out an invention for each vague notion, because sometimes they can generate a different approach. eg If it turns out water/air combos dont float, how can we make them float... that sort of thing. Sometimes I dont even try to learn the physics, because it can restrict the thought process to one particular direction. I'll do the thinking, then do the research only after I've thought of as many different affecting forces that MIGHT be at play. 

I find as a result, almost everything is worth exploring. I think I've learnt more from things that didn't work than from things that did, but I think there is 15% chance that that idea will either work, or have some payoff at some point. Each new thing I discover about the universe and how it behaves makes the next thing that much more apparent an accessible, and I'm getting better every day with being able to pick the things that might lead to something.

I tend toward a test, after dancing with angels on pin heads for a bit. It's nice to know one way or another 

And this...

I thought this might be a good way to deliver air if the second hypothesis is correct. ie That an air lift works by pushing water up with the air...

The general idea was to create a PVC air trap, set at an angle and pivoting around an axle mounted on it's lid.

This would allow the device to dump all its air at once, but only when it became full, so that it would dump a lot of air quickly regardless or the rate the air was being added.

Re-looking at that original drawing of the multi-stage air lift, I don't think the chambered air tubes would be needed at all. The air would just dump under the side.

[The future]
I'm being told about something called a geyser pump that appears to work by dumping a large lump of air into an airlift all at once. Exactly how it does this is still a bit of a mystery to me, but I'm looking into it.

To be honest, this pressure stuff is a little baffling to me. I've never really understood pressure.

For instance...

For years I've always been puzzled by submarines, pressure, and waves.

If a submarine is at it's maximum depth, and then a 100ft wave goes over the top, does the sub feel too much pressure, and get all squished?


I have no idea.

I also don't really care, but I definitely have no idea.

This post is a mess. I'll do better soon.

*opposite to overflow**

**Yeah, that's a word now

If I was Santa, I'd still do 120 Things in 20 years, but I'd have all my helpers experimenting with building a better air lift for everyone's aquaponics systems. Only 318 sleeps to go.

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