Aquaponics - Safe fish hides

I've been very lucky since being unlucky.

The first fish deaths I had over the first months after cycling my aquaponics system, turned out to be caused by a plant that seems to be only poisonousness to fish.

Since then, I haven't had any more deaths, but it occurs to me that it might be possible for a fish to die, and I might never notice. Or at least not notice before it began to decompose and foul my water.

The eleven silver perch spend most of their day hiding from imaginary predators in the halved terracotta pot I put in the water for precisely this purpose.

You can never be too safe from imaginary predators.

But if and when I make a bigger system, I think I'll make some fish hides in such a way, so that if a fish dies or is sick, it cant just get all sleepy in the hide on the bottom.

I suspect the easiest way to do this would be to suspend the hide a little way off the bottom, of even high up near the surface. That way if anything dies or is struggling, it will be obvious, on the bottom rather than hidden from view.

As a temporary measure, I've cut the base out of my terracotta pot using my preferred precision tool,(hammer) so it's now a tunnel. The powerhead is pushing flow directly into the hide so if anyone gets sleepy, they will get pushed out the back, and should become visible.

I'm not expecting to lose a fish, but simply had the thought because of hearing about someone else's problems.

Snail farming - Farm idea

It occurred to me a while ago that the basic aquaponics system could be adapted to growing snails. This came about partly because my lease says I'm not to have fish, but mentions nothing about snails, and partly because I couldn't help it.

Sometimes stuff just occurs to me.

My current aquaponics system looks like this. Water (and fish) at the bottom, veggies growing in an inert media in the container above.

I could just add snails to the top garden section, but they would eat everything to death within seconds.

My plan would be to restrict how much of the fresh growing vegetable matter they could get at, in the hope that the plants could be kept alive for ever.

It would look something like this.

"A" and "B" would be the normal water levels of the flood and drain cycle, And "C" would be a once or twice a day rinse to bring down solids from the snail area. Those brown things are my depiction of snails. Those green things are lettuce growing.

The snails would be in a stainless steel wire cage, which would allow them access to only the tops of plants (lettuce etc) growing in the aquaponics system.

The cage would be covered on all sides so the snails couldn't escape, and would have some terracotta pots to hide under, water, calcium supplements, and whatever else it turns out snails like.

The rinse cycle should in theory, pull solids down into the garden level, where added compost worms would digest them and spread them out,  so the nitrifying bacteria in the media could do its thing. This would in turn feed the plants that would partly feed the snails.

The system wouldn't work as an endless loop because I'll be pulling snails out for escargot. Once you eat something from the system, the removed energy needs to be replaced. That's where the veggie scraps come in. Since moving from the country where we had all kinds of scraps eating critters that did things like convert scraps to eggs, I've become a bit freaked at how much food we throw away.

Gram for gram the scraps represent almost as much as we eat. Much of it will make snail food.

So that's the plan, but plans have a habit of changing around here.

Inputs would be household kitchen scraps, and perhaps a little calcium for their shells.

Aquaponics - Moss

I noticed some moss growing on my scoria today.

I don't know what that means.

It's been raining quite a bit so it might just be rain, but if its not its a bit of a concern.

Its possible that there was a bit of settling of the scoria when I moved houses (perhaps cornflake manufacturers aren't lying to me after all). This might mean the water level is now coming too close to the surface of the growing media.

The water level is set by the standpipe in the bell siphon, so its the same as it always has been, but the lowering of the media means the plants are now also lower.

The plants are looking fine at the moment, and we have already started to harvest salads from the lettuce (we repeat havest leaves from coz lettuce until the plants get too ratty and then replace them). The baby spinach is not quite ready for a similar attack, but soon will be.

I have no idea if higher water levels will cause any problems, but it's normally agreed that the water should only come to within a few centimetres of the top of the media. Plants tend not to like it when they get too wet.

I'll keep a close eye on it and in needs be add some extra media or shave off some height on the standpipe. My plan would be to add media and then gently pull up the plants to a new level. I have no idea if this will work but these things have to be tried :)

So far I've found aquaponics to be very accommodating and gentle to the plants whenever I've transplanted them, or even lifted them out to look at their roots.

Snail farming - Reproduction

[Edit from the future - QI featured these facts in their show last night. Other than knowing the Latin name for a giant squid, the facts I add to this blog might be my only chance to win a pub quiz, so the less they appear on TV the better]

My garden snails are Helix aspersa and they reproduce in a truly astonishing fashion. I'm not talking about "A little odd, but what they do in their own homes is up to them". I'm talking some really strange stuff.

Firstly, the best part about snail sex is that everybody walks away pregnant. Which is nice. It must be a lot easier to get your partner to come with you to your birthing classes if they also need to learn how to breath.*

Helix aspersa are hermaphrodites meaning they have all the required kit of both males and females, and although it's not normal practice among snails, its actually possible for them to self fertilise.

Normally (whatever that means) two snails participate.

It's starts with a cuddle.

And then (and here's where it gets interesting) they each whip out a hard calcium spear and go about stabbing the other with it. Through their body. Stab. Into their skin. Through their skin, and into their body. Where their calcium dart adds the required fertility to the others snail's eggs and, in turn is similarly also stabbed.

That blur is camera shake and not crazy fast paced snail action.

From what I've observed in my garden, the dart seems to be left behind. ie it breaks off.

Different strokes for different folks I guess.

It's all part of the rich tapestry of life.

The dart looks like this. 

The one pictured here is around 4 or 5 millimetres long.

Cupid's got nothing on these guys. In fact it's possible that my new and tasty garden dwelling buddies are Cupid's original inspiration to take up the bow and arrow in the first place.

*TV told me.

Aquaponics - Fat Film Technique

I bought some of these in the hope that they would fit into my thin film technique tubes.

It's actually a seed raising tray, but the pots all come out of the tray so I thought I'd be able to use them.

It would of course involve throwing away the tray, the plastic wrapping, the cardboard advertising on the front and back, and the reciept, but that shouldn't pose a problem for me as I'm a white middle class man from a developed nation, so waste is in my genes.

But it gets worse.

They don't fit.

The pot should be sitting on the bottom of the tube, or really close to it.

I should have measured* twice, bought once.

But like I said I'm from a middle class background, not a ruling* class one.

I'll take them back and try something else.


Aquaponics - Nutrient Film Technique or NFT

One of the best things about setting up an NFT or Nutrient Film Technique aquaponics system, is that I get to use PVC yet again. I dont know why, but I love the stuff.

As far as I can tell, Nutrient Film Technique, involves planting plants into little pots that sit in a channel with a thin layer of nutrient rich water flowing at their roots. The water is only one or two millimetres deep, so most of the roots have plenty of access to the air they also need.

I'm guessing the water migrates at least part way up the roots in that way that water does, but who knows.

Oval cross section NFT PVC tubes
Some time ago I got hold of these two PVC, oval cross section pipes.

They are currently sitting in the rafters of my shed, but I think its time to pull them down and incorporate them into my life in a more meaningful way. Not that I have anything against sitting in rafters if that's what you're into. But for me and my PVC, its all about getting down and being attached to a fence or something.

I have no idea where to get the cups from so I'm not sure If I'll have to make them or if they are an off the shelf kind of prospect.

Either way I'm going to have a go at this NFT caper, and see If it might be a way to get some additional real estate for my strawberries.

The plan, at this stage at least, is to attach them to the fence behind my little aquaponics system.

With a little slope built in it should be possible to pump water up from the fish tank (hose drawn in orangy-brown*), have it flow through the top tube, and empty from the left into the bottom tube(sloping slightly to the right), where it would then flow to the right and empty back into the grow bed or directly back into the fish tank.

Those green things are my stunning illustrations of strawberry plants.

See how they thrive?

Thrive plants thrive.

Plans have a habit of changing around here, but it should work. If it does work, I should be able to move the strawberries around, so that when they put out runners (strawberry plants put out runners (runners are little baby strawberry plants sent out on a stem to set up home next door to the original plant (generally speaking a very sensible way to reproduce compared to all the carrying on everything else does))) I can set up a situation where there are vacant spots on either side to accommodate the runners.

[Edit from the future - there is some additional material on NFT ]

* Yeah! That's a colour!

Aquaponics - Poop

Common practice is to spread your solids fish waste evenly over the grow beds so as to avoid creating dead areas depleted of oxygen, and perhaps containing too much nutrient for the plants. People often add composting worms to their grow beds to aid in the break down of fish solids. The normal method of distribution, is to split your incoming water into several outlets. This is often done by making a loop of hose that surrounds your grow bed, and drilling holes so water enters from all around.

I'm trying something a bit different. [note from the future - I'm currently engaged in a debate as to this being a good idea or not, so copy this approach at your own risk (even slightly more than everything else of here should be copied at your own risk)]

A few weeks ago I tried adding the water directly to the siphon area. Rather than going through the grow bed media, it just feeds into the gap between the media screen and the siphon. What this means is that the clear water spreads throughout the media, but the solids get dumped back into the fish tank.

Normally, the point is to try to get the solids out of the fishtank, but this way the solids get broken up each time they get dumped back into the fish tank. they just seem to vanish after going through the system a few times. At any time, when you look into the water, there is about the same amount of solid fish waste in the water. It's normally queued up in a bit of a whirlpool that forms near the pump. At any one time there might be a teaspoon of solids and bits of who knows what in the little pile.

It's possible that this will all end in disaster, but it's also possible that this is a viable method of mechanically breaking down fish solids before they do into the grow bed.

Because I'm lazy, it's also worked out nicely that I didn't even have to make anything. All I had to do was extend the pump hose so it would reach the siphon.

There is some chance that the solids are building up on the far side of the media screen (in my case, the soft drink bottle that keeps the grow media away from the siphon) but the water rushes to the siphon quite quickly once it triggers, so I suspect it would draw any solids back through the screen and into the fish tank.

I'm keeping a close eye on it and will let you know if any further developments manifest.

By the way, that's strawberries at the top left, three week old coz lettuce (from seedlings) top right and bottom, and the little ones in the middle are baby spinach (also planted three weeks ago from tiny seedlings). Interestingly I planted the spinach on a hot day in the middle of the day and they all wilted to the point where I was sure none would live. Two days later they were still alive but were all wilted to the point of laying flat on the ground. But now every single one is thriving.

We should be harvesting individual salad leaves within a week.

Aquaponics is like intensive care for plants.

Aquaponics - The state of the fishies

Happy birthday 120 things in 20 years!

I was looking through my youtube videos and was quite surprised to see how much my fish had grown. I forgot how small they were when I first got them.

They now look like this. The largest is probably around 22 cm long. The water temperature is only 10 degrees c in the morning because of overnight heat loss, (it's winter in this part of the world) but I'm running a powerhead (a powerhead is a fishtank water moving device that acts more like an outboard motor than a pump) to keep the water moving. This seems to be making them more active, and they are eating much more than I would expect.

Normally silver perch shut down at around 16 degrees c and eat only a tiny amount until water temperatures improve.

They seem to love the high flow rate and actively seek it out, even though there are calm areas in the fish tank.  The following video is in 10 degree c water.

They used to look like this!

I'm back


I'm back.

Or so it seems.

I won a photo competition. Which is nice. I found some landscapes in my aquaponics system and spent a few hours with the camera. The pic that did it was the one above. It's a photo of my small blue barrel aquaponics test system. That's one of my little silver perch featured in the foreground, and the black algae 45cm away on the rear wall of the blue barrel is exactly that.

What a difference a frame makes
 For those that care about such things, the pic was taken on a little digital happy snap Canon PowerShot A490 on auto mode (with some adjustment of the flash output by partially covering it with my finger) no post production was done, other than cropping the image a bit to get rid of the edges of the barrel and the water flowing in as these things ruined the illusion. So basically the image was just taken and not interfered with. The photo to the left is not the one it was cropped from, but shows what the scene really is.

And they say photos don't lie.

I've also moved home. We are now conveniently close to some things that are good to be conveniently close to, and depressingly far from some other things that we loved.

In the time I spent away I didn't do much of interest, and almost totally failed to learn anything new, so you haven't missed anything by my lack of posts.

Because of my new location, I don't think windmills are going to be acceptable. So I'm thinking of growing some snails. Snails tend to be a bit quieter than windmills. Is quieter a word. It should be. There are already stack of snails in the new backyard so I'm off to a good start. I know a bit about snails, but I want to develop a new way of growing them aquaponics style.

Part of the problem is the lease on my new home explicitly states that there are to be no fish. Inside, or out, so I'm hoping to power my veggie garden with snail poop.

Oh well.

Stay tuned for more "Things".

Popular Posts