Backyard Aquaponics
A place to discuss aquaponics

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Well the recent spate of hot weather, has given the chance to experiment a bit more.. with my relatively small system, protected from direct sun and relatively insulated and protected

The first comment is that you guys are correct, in that the Maths are not right for productive cooling via the Air-Supply.. The is just so little "Cold=Power" in the air that it will take a massive amount to actually cool.. and then it becomes a case of diminishing returns..

The simple reality is that we are constantly advised that pumping HOT AIR into a FT will raise the temperature, and thus it must also be fact that pumping COLD air, won't..

That is what I found... I could halt the inevitable temperature rise, by running the Air-Pump inside the freezer, and Insulating the air-line as if it were a refrigeration line..

I also took a larger Air-Pump inside the house, and using Air-Conditioned room air, and force-cooled pump and sucking the cold air off the Air Cond, I had and small effect..

Anyway - all good and unproductive fun, but the ONLY real way to cool is via a Heat Pump and direct contact cooling..
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So who's got trout that are still fighting on?

Mine are still battling on.
Bore water is a godsend for cooling the IBC!!!

I've got around 7 or so left from 20. A couple of small ones and a couple of bigger ones. The highest water temp I've had so far was 23.6°C and they coped well. I'm going to pull out a few soon to smoke and if the temperatures hold I might just leave the small ones in.

Sounds good! I was impulsive in September and bought 200 25mm fry from the Ballarat hatchery, so now have 200 or so 80mm-100mm fry that i'm keeping cool!

I lasted through the worst of the 40+ degree days, so I think I might just make it through the summer .

Just a thought to everyone cooling their water - if your town water is safe for the fish without dechlorination, and the temp of it is under 20 degrees, you can dump your IBC down to 20% and put 700L in it, which dramatically cool it.

I know its a waste, but you can flood irrigate your garden or lawn on the worst days, and at $2.3 a kL, it is probably cheaper than running a freezer to cool the water.

I don't use town water for this, but the bore water that is 18-19 degrees sure does the trick

Having a bore would be handy, nice cool refreshing ground water is great.

I found the town water tends to be warmer than my system water so topping up when it's hot just makes things worse.

I just pulled the last of my trout out. Tank Temp got a to 27.25 so that was as far as I was willing to go. Still got 98 3-4cm in the other tank doing well.

Wow that's really hot. Everything you read indicates anything over 22 degrees is leathal for trout, but everyone seems to have anecdotal evidence to rebuff that!

I think the key is keeping up the dissolved O2 level as much as possible. Without additional aeration I'm sure they'd be dead long before it got to 27C.

I still have around a dozen trout still kicking. Water got to 26c the other day, but has dropped to 21c today.

Fires, now flooding

It was a bit touch and go for a few days there, but sam, its returned to 20 degrees for me