Aquaponics Adventure Mark II Part VIII

Aquaponics February 12th, 2009

Once again, it’s been a long time between posts. Sorry about that. What can I say? I’m lazy.

The story so far can be traced from my last post. So whats news? Well, the short is this: Plants are great, fish are still not great. But before we begin, check out these little guys:

I’ve got no idea what bugs they are, but they’re pretty cool. Anyway, what were we talking about? Err… Vegetables growing in my Aquaponics system in Canberra.

Some evidence (for the unbelievers)

So in terms of vegetables, I think I’ve done quite well. I can’t use enough silverbeet, it loves it. The toms are ripening and I’ve eaten a few and they’re tasty as. Now the other side is fish. Well….. lets just say Christmas wasn’t easy on them. So remember I had those nice big fat ones? I went away over christmas, and the DAY before I left, I noticed they wern’t healthy at all. I think I’ve now completed the set and had every fish problem known to man.

It may be my only purpose in life is to serve as a warning to others. Time for the obituaries.

I don’t have much experience in this kind of thing, but I believe the redness like this fellow indicates ICH.

I believe this guy has Dropsy (it could also be “lateral line disease”). You can’t see it on the photo, but the other side of him is swollen out – he looks like he is pregnant on one side of his body. You can definitely see the hole in his side though. It’s got a secondary infection.

This is another one, fished out a few months later, with the same symptoms (this one was dead, where as the one above was still kicking). I think it’s Dropsy, but would be happy to be corrected. Dropsy is an internal bacterial infection.

The fish below has “hole in the head” which is bacterial too (probably all the same strain). You can see how some of the scales have peeled away from the skull there.

And then there’s the ones I killed due to stupidity. I put 2 in a bucket of salted water to try and get all the bacteria off them, and left them in there a little too long (i.e. I forgot about them for an entire day). So they died too.

I guess the worst time was over christmas. SO. Don’t give up. What went wrong? Why am I struggling with fish health? I think I have two reasons.

The first is the bloody weather. Fish don’t like it if water temperatures swing about all over the place. I think the fish gets stressed if water temps swing 5 degrees in a short period. Last saturday was 40 degrees in Canberra, today is 18 (min of 11). My system only has 1500L of water in it, and it’s all sitting up there exposed, with the bathtubs acting as heatsinks, so I think my swinging water temperatures are contributing to the problems.

The second problem is Nickel. Yes Nickel. I’m using bathtubs, and I’d heard that the enamel on some bathtubs contains lead. Obviously you don’t want that in a recirculating system, so I went and had my water tested:

So that doesn’t mean a lot to me, so it probably won’t mean a lot to you. But suffice to say, the guy on the other end of the line said “Your lead levels are fine, but your nickel levels are very close to the limit” (he was talking about safe drinking water). A quick search online found that Nickel can reduce a fish’s immune system in much the same way as Copper. So how the frig is Nickel getting in there?

Here’s a photo I took way back when I begun this project:

See that big nasty exposed area there? I reckon that’s sitting there, in the slightly acidic environment of my Aquaponic setup, and leeching Nickel into the water. Goddamnit. Someone told me that Nickel was often used to bind two metals, so it could be used to bind the enamel to the pressed metal underneath.

So what am I going to do about these problems? I’m going to go Bigger and Better.

The only way I can solve the heat problem is to move somewhere nearer to the coast? Nah, usually you solve those problems by adding more water mass. If it were 7000L instead of 1500L it would take much longer to swing. So my next system is going to have a much larger water body.

As for the Nickel, well, I could rip out the plants, take all the gravel out, line it with EPDM (pond liner) which is potable and would also insulate the bathtubs a little.

But I’m thinking, bigger, better. So I might just let this system run for a bit and see what happens, and I’ll start getting the next one up and going.

2 Responses to “Aquaponics Adventure Mark II Part VIII”

  1. Darren Says:

    Hey Gemmell. Nice summary. I think you have hit it on the head with the nickel. That and the temp fluctuation. Time to go big. Get some trout happening in that pond of yours.
    Good to hear from you.

  2. A Thought Adrift » Blog Archive » The OLD system Says:

    […] last time I talked about the old system was back in this post way back in Feburary. At the time, I’d just managed to figure out that Nickel was leaching […]