Canberra Aquaponics: Trout season ends in December

Aquaponics January 18th, 2010

Well, Trout season ended just before Christmas. Here in Canberra, we get days of up to 38 degrees, my water temps were getting up to 27 and the trout really REALLY didn’t like that. It’s O2 starvation – as temperature rises, the saturation level for O2 drops. So basically it gets to temperatures where you just can’t get enough O2 into the water and they go belly up. In the mean time though, I’ve been having plenty of trout.

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).

2 Responses to “Canberra Aquaponics: Trout season ends in December”

  1. Darren Says:

    What a great website.
    Im also from Canberra and am thinking about getting into aquaponics for some time now. Ive got some equipment/tanks etc but am still reaserching things as it seams that its so easy for things to go wrong. Selecting the right fish for Canberra was a question that i had but I think you have answered that.
    Is it possible to see your system sometime?

  2. Paul Nock Says:

    Hi Gemmell nice site, found it through your Link at BYAP, I will read more when things slow down

Leave a Reply