Anything that is essentially an iterative methodology is labeled as agile. And because most processes are iterative due to the nature of projects (i.e. requirements change, regardless of software industry) pretty much every software process out there is agile. Which of course means that the “agile” is completely redundant and can be dropped and we can return to talking about processes, rather than agile processes.

I thought of an analogy which goes some way to explaining my distaste of the term “Agile”.

 “Agile” is to software process what “award winning pies” is to a bakery. 

i.e. What bakery doesn’t have award winning pies?

Essentially any process, agile or not, has a series of steps to follow, and a bunch of techniques and tools which help software quality (e.g. pair programming) or some other software or project attribute (e.g. you measure earned value to predict completion time). If you take anything which is iterative and produces something, and then grab a bunch of these techniques, and give it a process metaphore (e.g. SCRUM has “sprints” etc) and you’ve got yourself a new agile process. No wait, let me take that back, you’ve got yourself a new process. We don’t need the term agile, because it doesn’t mean anything anymore.

Firstly – why would you do it? Well you can grow some protein onboard your ship – you can’t exactly grow livestock so apart from protein in legumes etc this might be the only way.  Secondly, this is dirt free, so you don’t need to worry about dirt getting in your systems and cutting them to pieces.  Space ships are all about recirculation, this is a very low tech recirculation system.  The added bonus being that the plants scrub the air of carbon dioxide.

Space throws up a whole bunch of problems. Firstly, how would you do it? Well I’d do it by grabbing an asteroid that’s mostly water ice, and build a structure around it. You then add another module which has hydroponic trays full of plants.  The biofiltration is done by a barrels of “bioballs”, or possibly just by bacteria growing on the walls of the structures.

Do we need gravity? Maybe not, the plants will grow towards light, and the roots will grow towards water, but gravity is useful. For starters, how would you keep the water inside the grow trays? I think you’d be fighting a losing battle, but if you had gravity – it doesn’t need to be much, then at least the water will stay “down”, and can be made to flow along the bottom of the channel. Dunno how fish like zero gravity – they have a swim bladder which enables them to go up and down in the water column, so I guess we need SOME gravity. Maybe fish have fine enough control of their swim bladder to handle low grav?

I’m not fluid physicist, but so long as the fish tank was “full enough” then you wouldn’t have too many problems with the fish getting stuck in a bubble of air and expiring. Plus I think the fact that you’re in a gravity-less environment would mean that the fish “flipping” about would actually have some effect on the air/water around it and eventually it would find itself back in the water. A bit of gravity might help with this as well, maybe you could pressurise the sides of the tank so the water stays as a ball in the middle? I dunno, probably not possible.

The fish need oxygen in the water – this might be a problem. The plants provide oxygen, but whether they provide enough oxygen for the fish to consume is another questionable. (Aside: I wonder why astronauts don’t have a massive vat of algae to do their CO2 to O2?). We wouldn’t want the whole system to consume oxygen.

Apparently water ice asteroids in space have quite a bit of Ammonia in them. Sheesh, that’s exactly what an Aquaponics system excels at. So when the ice has melted down, you can run the system for a couple of months and it’ll consume the Ammonia (and the plants will grow! Hurrah!) and by the time you’re ready for fish, it’ll be all cycled because it’s consumed the Ammonia present in the ice asteroid, ready for the Ammonia produced by the fish. Maybe NASA should explore using this high Ammonia ice to grow plants without the fish as this could be done right now. By product is drinkable water or oxygen if you want to go to the effort of splitting H2O.

A spinning ship provides the slight gravity that you need, it also means that you can emulate night and day.

Heating is another issue, it’s cold up there.  I think you’d have to filter the sunlight – I think direct sunlight is very dangerous, and the plants would probably get smashed by it (that’s why our ozone layer is so important), so we might need to have some sort of filter there. But if we had that, we’d essentially already have a greenhouse. I suppose you could do everything with closed boxes and awesome insulation for your modules, and use growlights for the plants, but I like the idea of using the sun.

I suppose we really need to close the cycle a bit more – the fish would need to eat plants, maybe we could use plant waste and turn it into worms (or even the worms compost our bodily wastes ….). Otherwise you’re going to need to take up a whole bunch of food for the fish. Though if you’ve got carbon dioxide, water and sunlight, you should be able to grow food for fish like you can grow plants for humans. Maybe you’d need to create more of a food chain (i.e. watersnails which convert algae to protein, fish which eat the watersnails and grow).

I dunno  - there are probably a million flaws with the idea, but it’s very blue sky dreaming and I love that kind of thinking. Give it thirty years! “Every deep space ark ship should be fitted with an Aquaponics system, and for the best space Aquaponics systems around, you need to talk to the experts“.

Then you should start to worry. This is caused by an overload of protein, which is a precursor to an overload of Ammonia, which is a precursor to lots of dead fish. So it’s a bad sign and should be heeded. Generally this is caused by overfeeding, and sure enough, on checking the bottom of the tank I noticed a buildup of uneaten food. Note that fish like trout and silver perch eat as the food falls, and once it’s touched the bottom generally goes untouched (maybe the fish have a 3 second rule?!). My problem is that my fish food is a little bit too small for them, so quite a lot makes it through the swarm and to the bottom.

Anyway, it’s easy to fix if you catch it at this stage. Vacuum the bottom of the tank (just siphon it out onto the beds where the worms will digest it), and turn your pump on so it’s cycling for 24 hours, this should digest the extra load and the system should return to normal. Oh, and stop feeding so much or make sure they eat it all as it falls.

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”.

….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.