Aquaponics - Two year old silver perch

Trying to measure a fish without disturbing it turns out to be a very tricky thing.

Eventual I managed by taking some video and then grabbing a single frame from it to turn into a happy snap.

Even then it's difficult to make out.

I think it's around 275mm long.

That's it's tail extending back a little behind the ruler.

They are roughly two years old, and I'm guessing it would weigh around 350 g.

It's not a lot, but still not bad considering how often they went without food during all the problems I had with poisoning them etc.

I suspect I could have seen double that weight if I had fed them as much as they wanted all the time. So I think it's time I got the demand fish feeder working. There hasn't been much point over winter as they don't do a lot of eating, but spring is in the air, and I want to get some more fish. It's also about time I did something about completing the fish feeder project.

I seem to be half doing way too much stuff of late.



120 Things in 20 years - If an aquaponics task is worth doing, and to get to the end of a task you must pass through the middle, then it must be worth half doing.

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Electronics - Power supply

One of the biggest problems I have with designing electronics is that I don't know anything about it, and don't know what all those little components do, so I designed this....

There are lots of bits missing, but I didn't want to go any further without getting some input from someone who knows this stuff, so I thought I'd post it any way.

It's more of a question than an answer.

"Is this something?"

The switches in the dotted line boxes are controlled by a chip.

The plan is that the capacitors would be charged either in series or parallel, so chip compares the voltage of the caps or source, and compared to the desired output voltage, it could then mix whatever capacitors it needed to achieve  the desired output voltage. With the battery (right hand side of the circuit) disconnected, the capacitors would be charged. Then the source power (left hand side) would be disconnected, the number of capacitors needed would be calculated depending on desired voltage, then they would be opened to the battery. So it might charge all the capacitors in parallel, then discharge the required number into the battery in parallel (or whatever).  This might happen a thousand times a minute or something.

I'm trying to create an "anything in, anything out" power supply that doesn't waste any power. That way I can charge my battery on my boat form a solar panel, plus a bit of wind power, and whatever else I happen to plug in.

I doubt it will work.



120 Things in 20 years dropped out of Eh?lectricity school. Can you tell?

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Aquaponics - Only very slightly kooky carrot

I was expecting a lot more interesting looking carrots, because I was led to believe they would all resemble Elvis/whatever you normally focus on, in a crazy attempt to grow toward the nutrient.

But I've nearly harvested all my carrots, and this is as kooky as I've had.

Not so kooky.

They also taste great and are super crunchy.

I cant help feeling that if I spent the last couple of months in wet gravel, I might not maintain quite so much crunch.

Really, really crunchy.

This one is getting on a bit, and it's probably the case that it was always this carrots intention to grow this way, at this time, no matter what it was standing in for the last few months.

I think I can safely say that in my system carrots grow just fine.






When asked in a recent interview why some people have a difficult time growing carrots, and other have no problems, 120 Things in 20 years replied  "Who knows? Carrots keep their own council."

It was a short, imaginary interview.

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Aquaponics - Solids removal

I'm actually a firm subscriber to the idea of leaving all solids in your aquaponics system, but I don't really have anything to inform that decision other than my thinking it. 

So we cant have that.

A healthy system can absorb a lot of fish waste and solids break down in no time. There are worms to help with that in the growbeds, but even without worms, friendly bacteria are always there to do their thing.

There's also the point that removing solids is removing hard earned nutrient from your system that the plants need.

There's also the fact that as my system stands now, I have a nice feeling that I'm working comfortably within natures guidelines and margins for error.

But enough of the sensible reasons for not messing about with solids removal. I'm going to have a go at it.

There are a few experiments from my recent past that I can call on. One is the swirl filter and it's followup, the self cleaning swirl filter. The self cleaning swirl filter was designed to separate solids, but keep them in the system, and I encourage you to click on the "self cleaning" link if you feel you might enjoy watching a video of fish poo swirling and settling. The reason I made it was to gain a source of clean water for my NFT (Nutrient film technique) pipes, but it might prove useful in this current endeavour.

I might also need a bit of electronics.

And an invention engine.

And a bit of a mental shift. I think I need to focus on water removal or recovery rather than solids removal. I need to get the water solids mix dryer and dryer.

Currently my plan looks a bit like this...

Step 1. Split the solids from the majority of the water flow using one of my self cleaning swirl filters. I suspect I'll be able to take out 90% of the water at this stage. It look like I might be able to do this stem more than once to get even more water out.

Step 2. Further separate the solids using gentle flow of the remaining water over or through a mechanical filter. Apparently, this will take the form of a conveyor belt sieve that slowly or perhaps intermittently eases solids from a water bath. At least that's what the invention engine seems to think. 

Step 3. Automatically convey the solids to a worm farm so I can add household veggie scraps and create high protein fish food. By returning the fish waste as fish food, I can still keep a natural eco-loop going, and continue to feel good about my system. Also, the fish really like the worms, and in winter when silver perch go off their pellet feed, it might be a good way to keep them growing.

Two things the final design will need to accomplish are that it will need to be very reliable, and that it will need to be very automated. I'll need to be able to go away for a week and ignore the system, and I'll need to create some failsafe system to make sure that I dont end up overloading the growbeds.

There is a great danger of overloading the system, because in order to have enough nutrient for the plants, I'm going to have to overstock my system with fish if I'm going to remove most of the solid waste.




120 Things in 20 years sees me cautiously optimistic about an automatic, aquaponics, solids removing, worm farm addition to my system.

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Thinking - Population density, innovation, and some evolution

I've just spent the last two months testing my invention engine by not using it.

It's the last of it's formal tests that I have in mind.

The test is to see if it really does anything, or if it's just me coming up with ideas that solve the problems.

I for one can see the difference.

Lately my ideas have all been a little thin, impractical, had no sense of direction, and seemed to involve phlegm. That last one may in fact account for all the others, but I've never been one to let reality crush a story.

In Australia, we (white invaders) have this traditional ingrained presupposition that we are all highly skilled in making do. We feel a country wide enthusiasm that makes us believe we can fix stuff, and that everything will be ok, as long as we have a bit of fencing wire. (I suspect north america has the same thing with gaffer tape) The result is we can be left as a wire-bound backwater in the struggle for national identity.

I'm not really sure where I'm going with this, so bear (forbearance, not the big furry thing you never want to find in your pantry) with me and see what happens.

Birds are dense in the head.

Their brains are packed with a stack of connections. More per cubic whatever than we have by a long shot.

The secret is in needing to be lightweight.

Now I have to mention evolution.

I've been avoiding this for a long time.

Evolution, as we know, is real.

It's a fact.

It happens all the time and is not something relegated to the past. It's something that happens all the time and was going on this morning before breakfast.

Some guy named Darwin came up with a theory called "Natural Selection" that speaks to what powers it... to what does the selecting of one critter over another, and leaving them safe to mate with the other successful ones, but that's just a theory as to how it happens.

The fact that evolution occurs isn't in question.

Anyway...

Some states are great and some never make it. And lately I've found myself wondering what it takes to make it. It's clear as a species, that we are moving away from joules in our diet as a predictor of a country's success.

If joules still rated as a success marker, I for one would be right up there as a candidate for some kind of award. I have virtually unlimited access to calories, but I'm not sure if it would do me any good. And even less sure it does my country any good.

So if not calories, then what? Some say necessity is the mother of invention. I say necessity is the non gender specific parent of making do with a bit of fencing wire.

I think the thing that creates true innovation is discontent.

The result is that it's not the meek that will inherit the earth...



It's the miserable.




120 Things in 20 years - In thinking  "population density, innovation, and some evolution", it seems everything is progressing according to plan.

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Thinking - God(s)

I'd like to ask everyone to petition their deities for a cessation of bad stuff effective immediately.



120 Things in 20 years, Bahhhgh!

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Aquaponics - Nebuliser

We don't like zeds in this country.

That's why we spell words like "nubulizer" with an "s".

I pretty much spell how I think words should be spelt, and let Ubuntu take care of the rest.

But...

This bit is the bit of a medical nebuliser that seems to make the fog.

As far as I can tell (I unplugged the hose when nobody was looking) the rest of the device is just an air pump like the kind people use in their aquariums or aquaponics systems.

The medication is in liquid form, and sits above the aqua disk. That's aqua the colour, not aqua as in Aqua-Man.

From what I can work out, the liquid spills under the disk via the tiny grooves you can see in the side of it, and then runs into a stream of air that employs standard magic to make it into fog.

With me blowing through it, it creates a spray rather than a mist, and it's not even close to a fog.

That's it working in my hallway.

It wasn't as bad as it looks on camera.

So I'm guessing the pump can dump a lot more air pressure to it than I can.

That, or the medication isn't water based. But I don't think it is anything other that water, because an angry nurse once told me it was drug laced saline [solution].

Up close it looked like this.

Not very foggy.

Even as it is, it might make a useful aerator.

There are a lot of different thoughts out there as to how aerators work in a fish tank, and I wish someone with an oxygen probe would just do a few simple tests and prove what's going on.




Oxygen (and other gasses) are soluble in water. A lake gets it's oxygen from the bit that meets the air. That's all good and well for a lake, but people like to keep more fish per cubic metre than a lake, so we need to add air. The air only dissolves into the tiniest depth of the top before that bit gets saturated with as much oxygen as it feels like carrying, and leaves the rest to float around, way up in the sky.

Unfortunately there is a lot of poor science out there telling us how and why water and air does all this. Actually the science isn't all that poor, but tends to relate to sewage treatment rather than fish tanks. And then does some dodgy science as well, but I digress.

1. Some say the air bubbles from an air pump in a fish tank simply increase the surface area exposed to the air. The fish tank surface, plus the surface of each of the many bubbles equals lots of surface.  It definitely does that, and there is the added benefit that the air is under pressure. The deeper it is, the more pressure there is. It turns out air under pressure likes to squirm it's way into water a bit more than usual.

2. Some say oxygen uptake is mostly done as the bubbles hit the surface. Something about the large increase in surface area as the bubbles break and splash around all over the shop.

3. Still others think that all that other stuff is happening, but the main thing the bubbles do is drag water up with them as they rise, and as a result, create a current in the tank, and constantly expose new lump of water to the air.

4. Many combine any number of those and some add some stuff about breaking surface tension. Some quote other people saying stuff about breaking surface tension being important, and get that mixed up with number 2 above. Others think that breaking the surface tension just means you don't get a sheet of water that keeps being the topmost layer because surface tension looks a bit like it might be a separate bit of water doing the surface tension thing, and it might not be moving much.

5. By far, the majority of people don't care because they don't have a fish tank, and the most intelligent of us that do, tend to ignore the entire debate and just stick an air stone into our tanks and attach it to an air pump.

Sadly I don't belong in that last category.

I care.

I've cared since I was a lad.

I had some guppies once in a five foot fish tank.

They all got out and went for a walk on the carpet.

They took all the water with them.

But luckily, a nice farmer took them all to his pond where they lived forever as far as I know.

Anyway...

I tend toward argument 3 with perhaps a little 4, but definitely aiming for 5.

I have only two fish in 1000 litres of fish tank, so there isn't a lot of competition for air, but I also have worms living and reproducing all completely under water. Two of my grow beds are run as constant flood beds. This means that they are always full, yet my worms don't drown.

This is a good indication of well oxygenated water, because it turns out that worms only drown when the water they are in doesn't have high enough levels of dissolved oxygen. Most aquaponics systems end up full of worms, even if you don't add them. I added some adult worms to my system ages ago, and regularly find adult and baby worms when I pull up a plant.

I have no idea how much dissolved oxygen worms need to thrive, and I cant find the answer anywhere, so if you know a student that needs an experiment, make them do it.

But get them to tell me the results.






120 Things in 20 years, I'm not really sure what this aquaponics nebuliser post was really about in the end, but I for one feel more informed as a result of having read it to check it to make sure not too much of my head fell out.

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