I know what you’re thinking – “eww maggots are in your compost”.

These are indeed maggots, but they are AWESOME maggots. Why? Because they’re Black Soldier Fly larvae (also known as Pheonix worm).  Below is a photo of the fly.

You’ve probably seen it around, they seem to be all over Australia. When they’re at the fly stage, their only concern is breeding and laying eggs. They have no mouthparts so they’re not the type of fly that comes into your house and buzzes around the kitchen scraps. They’re just not interested.

But the larvae. Well, they’re composting MACHINES. They will eat anything – which includes meat and citrus (something worms don’t abide by) – and turn all that compost into a rich source of protein – themselves. And here’s the kicker: they’re self harvesting.

What they do is grow from that small white stage, right up to a big brown stage like below:

Once they reach this stage, they head for a drier to environment so that they can pupate, so what you do is you put your bucket of scraps on a 45 degree angle, and the larvae get to this stage and then wriggle their way up and …. PLOP. They drop into your tank and are fish food. They are a fantastic source of protein and another step in “closing the loop”.

[There is a video that cannot be displayed in this feed. Visit the blog entry to see the video.]

….Well that’s the theory anyway. I’m still yet to actually make a BSF harvester. You can buy commercial ones (e.g. BioPod) but they’re expensive. The Black Soldier Fly seems to arrive in Canberra in Summer (around December). I don’t think it can survive year round. Anyway, go do some searching – there’s plenty of info on them out in the wild, youtube has some good vids. The BackyardAquaponics Magazine Edition 5 contains an excellent article on BSFL (Black Soldier Fly Larvae). If you’re at all interested, buy this one (the whole magazine is excellent though).

]]> http://athoughtadrift.com/gemmell/2010/02/26/supplementary-feed/feed/ 0 http://athoughtadrift.com/gemmell/2010/02/13/tomatoes-anyone/ http://athoughtadrift.com/gemmell/2010/02/13/tomatoes-anyone/#comments Sat, 13 Feb 2010 03:37:57 +0000 gemmell http://athoughtadrift.com/gemmell/?p=156 Just a quick update on my Aquaponics Sytem’s here in Canberra: I’m doing my best to make myself sick of Aquaponic tomatoes – so far I’m still loving them. They’re sweet, delicious, and they look fantastic.

Here are the pics, have you ever seen toms so lovely? I’m not sure what those red ones are, but they’re fantastically regular and bright red. The images look like they’re fake (they’re not! Click them for the high res versions). The smaller ones are Tommy Toes, the yellow one is a Wassippicon Peach, and the others are Black Russians (I think). This is from one picking session, new ones are ripening up every day.

This was taken way back on the 12 December 2009. I pulled out a whole heap to give some to the owner of the leg there, and for a family function.

And I’ve been pulling out a couple every now and then if we have someone over. This photo was taken on the 18th December.

And then finally, just before Christmas, I took the rest of them out. I was going away, and there was no way I was going to risk having my “crop” die and go manky while I was away. We’d been lucky up to this point – the days had been hot, but the nights had always been cool. I wasn’t willing to push my luck. So the rest of them were pulled on 22nd December.

So I have a freezer full of trout.

So do I run an empty system? Of course not. It’s Silver Perch time. This is a bit of an experiment because I don’t think we’ve got a long enough hot season in Canberra to grow them to a decent enough size for them to last a cold season. Really, we’ve got 8 months of 20 degrees or less (water temps) and 4 months of greater than 20.  Silver Perch like it hot.

Because my old system is … well … old, it is a lot more established and in my mind safe. So I received them 22nd December and I put them in the old system. I got roughly 150 Silver Perch and 20 Golden Perch delivered to my door. They didn’t like this much, with 25 DOA. Very disappointing, don’t think I’ll get them from there again.

And the rest were not happy at all – when they’re stressed they “flash”. They’re trying to rub their bodies on the bottom/sides of the tank to get off the nasty’s which are bothering them. This is very handy because you know they’re not well. So how do you fix them? SALT. Good old fashioned NaCl (not the stuff with anti-caking agent though!). Up the salt by 3 parts per thousand (ppt) – the fish can handle this no worries, the nasties cannot. It also acts like a bit of a stress relief tonic for the fish. 1400L of water means roughly 4.2kg of salt. That’s a lot of salt. I think this photo has 2kg in it.

Unfortunately this means the strawberries suffered (they can’t handle salt at all), but at least I saved my fish.

I should also point out that my old tank had lots of bloodworms in the tank. The trout didn’t seem too interested in them, but the Silver Perch… well … I’ll let the photos do the talking. The first photo is taken on the day I put them in. The second photo is the next day.

They cleaned it up good and proper!

This is the Golden Perch going into the big system. They were twice the size of the Silver Perch, and so they were eating them.

So now I’ve got about 100 Silver Perch in the old system, and 20 Golden Perch in the big system. That’s not many fish to sustain a heap of plants. So how are they doing? Well they’re doing OK. I’m wanting my tomatoes to fruit at the moment, so it’s probably a good thing that I’m not bombarding it with Nitrates. I’ve put in a massive dose of Seasol, which is a good source of Potassium.

Worms do a great job of cleaning up in the growbeds.

And my tomatoes are setting fruit nicely.

So all is well (touch wood).

Normally I wouldn’t really care, but I’ve just launched a business: Capital Aquaponics – I figured that I’ve learnt so much over the last 3 years (and there is a LOT to know) that I am now able to design a system that effectively side steps all those pitfalls that most people fall for when they’re starting up. Not only that, but I figure I am now able to go over someone’s house and pick out the best locations for all the components such that we can utilise any sloping land, light and shade sections of the yard, thermal masses etc etc. So I’m going to provide a service to those who just want to skip the painful startup and learn by mistake methods of building systems and help them design and install a system which will maximise the chance of a succesfull crop. Oh, and because I have built systems from all sorts of materials (bathtubs and IBCs, barrels, BYAP systems), I can pretty much do it for any budget.

I’m going to be selling my knowledge rather than kits, because I think kits are going to become more and more common as this Aquaponics thing really takes off. I’m all for someone going and building their own, it’s a fantastic hobby (gardening for engineers/blokes really), but if someone just wants to produce edible fish and vegetables on their backdoor in a really cool, sustainable and ecenomic way and NOT have to learn everything about the different techniques then I can do it for them.

Anyway, we’ll see how it goes. The site is pretty rudimentry at this stage.

I lined the bathtubs with bubble wrap and pond liner (EPDM), which is as safe as. The bubble wrap gives it an extra layer of insulation – you can imagine a metal bathtub would act like a massive heatsink, it’s in direct contact with the water, so it was inducing big temperature swings in the water which also stresses fish. So I killed two birds with one stone when I lined these beds.

The system had been left without fish, and even without cycling water, for about a month. So I was dubious as to how quickly it would recover. I was pleasantly surprised.

Just 10 days later.

A month later and they’re still growing strong.

The watercress is damn near escaping, and that bok choi you can see next to it ends up being this monster a good 4 months down the track (I was away!)

This was with a load of 50 trout. Notice how clear the water is – this system is a bit more mature, and seems to handle solids really well. The water is always sparkling clear.

I dunno what happened (brain tumor maybe?), but I didn’t take any further photos of the fish in this tank. Sorry folks.

The growbeds currently look like this:

We’ve eaten or frozen most of our trout – there are about 20 left in the big system, though water temps have been up as high as 26 degrees, so I don’t know how much longer they’ll live (but I’m going to find out!).

And it’s just not a blog post if I’m not in it looking like an idiot (note that this bag contains the only brown trout that I had in the system).

The moral of the story (if you got this far) – LINE YOUR BATHTUBS. It serves a double purpose – stops nasties from the bathtubs getting into your water, and helps heat retention.

]]> http://athoughtadrift.com/gemmell/2009/11/24/the-old-system/feed/ 1 http://athoughtadrift.com/gemmell/2009/10/28/continuing-ap-success/ http://athoughtadrift.com/gemmell/2009/10/28/continuing-ap-success/#comments Wed, 28 Oct 2009 06:02:18 +0000 gemmell http://athoughtadrift.com/gemmell/?p=138 It’s been a damn cold spring. I’m not really complaining because it means I’m able to keep my trout growing longer – once the water gets up past 24 degrees they’ll start to struggle. In the mean time however, I am harvesting about 10 fish a week. They’re up to about 30cm now. I have recently cleared out my growbeds to make way for the spring/summer veg. I had a LOT of flowers in there, and when I cleared it out I found celery underneath! Oh and a couple of artichokes which are starting to fruit.

Me and my growbeds. You can see the artichoke leaves sticking out the side there.

This is a shot of my aquaponic flowers in the first bed, with the second bed in the background.

A sweet pea flower.

Some kind of odd cricket on my strawberry plant (EDIT: It’s a Katydid which eats soft bodied insects, so it’s beneficial. I found out through this site).

This is one of the daisy plants. They outgrew everything, including silverbeet. Yes, I’m wearing a flower. Shutup.

Dinner.

5 Trout = 1kg. You can also see one I’d smoked the previous day on the left there.

Me + AP trout = happy.

Unfortunatley because I cleared out some of the bed it now looks like a bomb has hit it and is no where near as impressive. It’ll be back.

I have about 75 trout left. I’m currently exploring options as to what the hell I’m going to do with them all. I’m having just about every family member or friend over for a smoked trout dinner, but I’m still not going to get through them all (plus I’m going to be damned sick of them). Someone has suggested a vacume sealer and a good freezer…  it should keep up to 6 months in that. I think ideally I would like to cold smoke them as this preserves them.

I’ve been talking to a guy at work who’s big into trout. He’s of the opinion that the flesh is pale because it hasn’t been receiving enough Calcium. I’ve read this somewhere else as well – that you’re supposed to feed them yabbies and crickets and stuff to get them to have red flesh and strong flavour. Might have to start breeding yabbies….

All four are rainbow trout, the one at the bottom is a male which is why it has a deeper body shape, a hooked jaw, and milt:

Spring growth has kicked in, here’s me being an idiot in between my two growbeds:

Finally, smoked for 15-20 minutes and served with crackers.

I have another 93 trout left, so I might need a hand because trout don’t like temperatures over 24 degrees C (i.e. they die). So I have to get all 93 out and a batch of Silver Perch in.

Sorry for the broken photo links, I’m going to fix them up real soon.

A friend came over on the weekend and REALLY wanted a fish to try out his trout smoking skills, so I let him fish one out (lucky dip) and this was the result.

A little over 200 grams and 24cm long(ish). I know there are bigger ones in there. But there are probably smaller ones too.I’ve got another 2 months of growth before it gets too warm for them!

Here’s some pics of the grow beds. Note that I’ve got a lot of native australian flowers in there – the two of us can’t possibly eat all the produce from these systems, so I have to “bulk it out” with flowers… I need to to dose them up with Potassium quick smart so they actually flower.

A basket full of rocket and arugula:

Bok CHoi Ahoy!

Without the roots, 5.25kg

I ended up getting 10 mini bok choi plants off it, and a stack of massive leaves

So my aquaponics is obviously doing quite well. Fish are healthy and active:

Oh I should mention, the pH of the system was 6 or below when I got back from overseas – this was causing the plants to “lock out” trace elements. Not sure which one exactly, but I added a few kilograms of shell grit to the system which has buffered it back to 6.4 which is good for fish and plants (though I would like it a little higher).