Aquaponics - Over Flow

I wandered out to my system last night, and had what is commonly known as an HSM.

It must stand for Holy Ship Moment.

One of my grow beds was flooded, and there didn't seem to be any reason why.

This is the scene a few minutes after the pump was switched off.

There was water on the floor, and the pump was sucking in small air bubble through the little tornado that had formed in the shallow water over the pump inlet.

I couldn't figure out what was going on, so did a search of the system.

I found this blockage in the stand pipe.

It was stuck really well, but eventually to hammer it out with a length of dowel and a hammer.

The culprit, shown here, was a small piece of scoria.

This growbed's media is scoria.

I also found bird droppings. I'm guessing a blackbird was in there throwing things around and looking for worms.

I do actually have an over flow pipe, added when I first built the little system, but the input flow from my bigger pump is much greater these days, so the little pipe wasn't up to the task.

Even so, it's a good thing it was there because I think it saved the day by delaying the disaster until I discovered it.

I'll upgrade the pipe to cope with the new greater flow, and I've put a PVC cap over the media guard so that particular issue cant happen again.





120 Things in 20 years think the last thing an aquaponics system needs is excitement when it comes to overflows.

Aquaponics - Alf alfa sprout transplant test

I thought I'd test an alf alfa sprout transplant to see if there were going to be any issues.

The result was both a success and a fail.

I started with some normal alf alfa sprouts pulled from my sprouter device.

I figured half a dozen would be a good number to test.

I thought perhaps the shock of going from my perfect humidity, no wind, no real temperature swings, sprouting device might make them all kick the bucket when dropped suddenly into my aquaponics system.

The first one I planted was rested into a shallow hole made in the scoria. I figured I'd have to be pretty gentle with them because the scoria is a little rough.

I ate the rest, so I'm not sure this really qualifies as good science.

But after covering it up it looked like this.

I'm not sure if this pic is right after he transplant or the next day, but either way it looked like this the next day.

It was planted in the hottest part of a reasonably hot day, so I think it can be claimed as successful.

But the day after, it looked like this.

I had to dig around a bit to find it because whatever had eaten it, had eaten it down to beneath ground level.

I hate slugs.









120 Things in 20 years - And that folks, is why we should not eat the science, when testing sprout transplants in aquaponics.

Aquaponics - Absurdly low energy system test

I started work on my absurdly low energy test system and it looks a little bit like this.

Actually it looks exactly like this, because this is it.

And that's all there is gong to be until tomorrow at least.

The grow media this time is a product from Germany called Hydroton. It's clay balls that are puffed up like popcorn and are really nice to work with.

They are very clean, so all they needed was a quick rinse rather than the hard work that washing scoria was all about.

They are also great to work with.

Scoria was very sharp, and hard on the hands, but this stuff is a very different story. You can push you hand right to the bottom of the grow bed. I'm surprised it's stable enough for tall plants, but it doesn't seem to pose any problems.

I've read that it can float for a while, and mine is sitting in a half full tub, so perhaps it will settle a bit in time.

Because I've been feeding close to the maximum my system would allow, I should be able to compare scoria to Hydroton from the point of view of the bacteria colony. If I cant double the feed within a few months, it means the scoria is better, it will be interesting to see.


120 Things in 20 years, where sometimes, eventually, stuff like an aquaponics, absurdly low energy system test can start to take shape.

Aquaponics - Dipel works

If I hadn't replaced my first sentence with this, my second one would have made a lot more sense.

Actually it doesn't seem to have a smell to love, in the morning or at any other time.

But I didn't, so there you go. I hate censorship, even when I do it to myself.

Dipel turns out to work really well, and doesn't seem to have a smell or be toxic in any way. It's certified organic, and makes caterpillars dead.

In short, I love the stuff.

Dipel is a bacteria that makes caterpillars get a little ill and go off their food.

Sorry Vegetarians.

Do vegetarians kill caterpillars, but just not eat them? I'll have to ask my veggie friends. I'll get back to you on that one.

At first I didn't mind it when I was losing leaves to caterpillars, but when they started eating fruit on my tomato vines, I had to draw a line in the sand. Or in my case I had to draw a line in the scoria.

I actually like it when I see pests in the garden, because as long as they are not in plague, they keep the predators around and well fed. If the predators are not around when a plague brakes out, there is too much of a lag between the time of the pest and the predators breeding up enough to restore balance. As long as pest and predator are both in place, we see everyone getting along just fine. (providing you consider being attacked and eaten getting along just fine). I suspect things that eat grass always breed more readily than things that eat meat. Probably because you need to invest so much energy raising a hunter with the big brains and tactical minds and all, but grass eaters can get away with brains that spend more time thinking grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass grass.

Whilst some humans spend time pondering their relationship with grass, many others spend their allotted hours on things like war, driving really fast, and baking.

At first I thought the Dipel wasn't working because I didn't see any sleepy caterpillars lying about on my scoria. Later I found ants quickly whisking them away and then not spending their ant days waiting under the caterpillar tree in the hope for more. For some reason they just left one or two ants waiting and everyone else went home to watch TV or something. But after watching them for way too long I would see them come running out whenever I knocked off one of my dead caterpillars from the tomato vine.


120 things in 20 years - It's kind of, like, you know, about everything really.

Aquaponics - Home made media

I did an experiment last night where I mixed some clay soil from my backyard with some crushed up goat dung. The plan was to try to make something like scoria, for use as a home made media for a grow bed, but just to see if it could be done.

And voilà!

First, I spread some whole dung out on a tray. Then I made a mixture of clay,water, and powdered goat dung. My theory was that the powdered goat dung would create thousands of tiny holes in the finished product. This would create some happy housing for the nitrifying bacteria required by aquaponics.

I then poured the mixture over the tray of whole dung. The design behind using the whole dung was an attempt to make it break into irregular shapes later on in the process.

Next I set it out to dry. If I was making an amount greater than this tiny test, I would have poured it onto the ground in the sun. But it was raining so I put it on some foil, and dried it on the fire. DONT DO THIS AT HOME! It can smell a little agricultural. When the yelling stops, you know your tile is dry.

Lay it out and build a fire over it. You want your fire to be 900 deg C or more. Clay will undergo a permanent chemical change at around 600 deg C (don't quote me on that number) where it becomes no longer possible to wet it back down to clay. The physical water steams off at 100 deg C, but at those higher temperatures its not just drying the clay, it's actually changing it into something else.

I actually fired mine in my living room wood burning heater, but to make it properly you need the kind of temperature that makes iron glow bright cherry red (~900C) It's quite doable in a decent fire.(a match burns at around that temperature).

A normal pot would crack if treated like this but because there is so much organic matter leaving the clay body porous, we can get away with it. It doesn't matter if it cracks anyway.

Next. Smash it.(see)

Its done (see top pic)

Delicious.

I have no idea if this is practical or useful in any way to anyone, but it was in my head so it had to come out.

Aquaponics - My second system

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The new aquaponics system has started to take shape. We cut the first tank in half and it will become the grow beds.

Two 1750 mm x 1100 mm x 300 mm grow beds to start with and we may add another later. Two grow beds this size will feed my partner and me with all the veggies we will need but she's keen to try a cut flower garden as well, as am I. We have decided on pumps, sumps and plumbing  that should allow for some expansion.

I think we will need to brace the middle sections of the grow beds with some wire stretching from the center of one side to the center of the other to stop it bulging. Each bed will hold half a ton of scoria so there will be some pressure on the longest sides. Once cut, the tank halves lost a bit of their structural integrity, this was to be expected and should be easy enough to fix.

We are still struggling with the decision regarding painting with gripset51 or using a pond liner. I think at the moment we are leaning toward using pond liner simply because it will be faster and there wont be any drying time. And I hate the smell of paint. I also just get the feeling that even though its plastic the pond liner will suit aquaponics a bit better than paint.

Just in case anyone cares, from what I can work out a ton of scoria is roughly 1000 litres in volume (as bought in 25 kb bags from the hardware), and a ton of  7 - 14mm blue metal gravel is roughly 670 litres

A thousand litres of scoria bought in bulk will cost around AU$145 and a thousand litres of blue metal road gravel will cost around AU$90

Aquaponics - Grow beds

On day 4 I made life! Pictured is a coz lettuce 4 days after the seeds were sprinkled around.

When you first start running your system you do it without fish because the environment is too unstable. You can do it with fish but have to be very careful to avoid a stinking mess and some major karmic debt.


I'm happy to eat fish (and can cope with any fish deaths that may occur as a result of my eating them) but don't trust my new abilities as a fish farmer, so I'll be doing what is called fish-less cycling to get my system started. That doesn't mean you can't put plants in because, it turns out,  to cycle fish-lessly you add ammonia in some other form, and the entire process works just fine without the fish.. I'll talk a bit more about fish-less cycling in another post.


 A garden bed or grow bed (abbreviated in online forums as GB) is filled with some kind of gravel-like media so the plants have something to hold onto, and so the nitrifying bacteria have somewhere nice to set up house.

It seems plants don't actually like the exhaust that fish put out, but bacteria exist that love to convert it into stuff other bacteria like to convert into the kind of thing plants like.

Fish excrete ammonia, (fish don't like ammonia) some bacteria change that into nitrites (fish don't like nitrites either) and then some other bacteria convert nitrites into nitrates. Plants seem to like nitrates and fish don't hate nitrates quite as much as they hate all that other stuff. This process is known as the nitrogen cycle, and more information can be found here by clicking this.

The gravel that you use depends on how wealthy you are. You can buy clay balls that look nice, are great to work with, and work very well. Or, as I have you can use scoria (some kind of volcanic rock with lots of holes in it). you can also use gravel.

I used scoria (and a small amount of an experimental clay based media I made) because it cuts your hands and is difficult to work with. I'm not very wealthy. It was cheaper and it has a stack of trace elements that should make themselves available to the plants over time. My scoria is also red, most red stuff in rocks in Australia (I'm in Australia) is iron. Plants like iron. Scoria also has a huge surface area because of all the holes and because of its irregular shape, so there should be plenty of space for the bacteria to colonize and lots of cavities to hold water.

scoria looks like this (scoria doesn't always have a key in it)...

- the beasties live in the grow media. They eat fish crap and crap out plant food.
- interestingly a stack of fish eat plants, and those that don't, tend to eat things that do, so the entire thing can just go around and around for ever. Which is nice.

Those bacteria also eat fish food (or at least they eat the stuff that fish food will break down into), so any food not eaten eventually breaks down and gets absorbed nicely into the system (within reason).

By adjusting the height of the siphon's standpipe its possible (and desirable) to set the flood depth of the grow bed. Set high tide to a point just below ground level. I'm told 2.5cm below ground level is about right. Plants don't like to get too soggy and the bacteria don't like light so there is no point in over filling and its just going to waste more water to evaporation if you over fill the grow beds (I'm told aquaponics uses only about 10% of the water you might use on a dirt garden). Its also a good idea not to fill your grow beds all the way to the top with gravel either. Over filling your beds with gravel will end up with you spilling your media onto the ground every time you dig around or harvest a plant.

My grow bed takes around 20 minutes to fill, and around the same time to drain.  The pump runs all the time so water is flowing in the entire time, even when its also flowing out.

As a rough guide your media takes up around 60% of your grow bed leaving space for water in the other 40%.