Backyard Aquaponics
A place to discuss aquaponics

Hi Folks,

tl;dr Have any experienced users got any suggestions for water-cooling or discharging heat from the system?

I posted a few years ago about a simple goldfish-powered ibc system I had set up at the school I work at. It ran for a couple of years quite well, but the school is no longer focusing on Sustainability (it's been crowded out of the curriculum) so the system is now sitting unused at the school. I'm leaving at the end of the year and am hoping to buy it off them and take it home.

I have become a home owner in the intervening years and have the potential to do aquaponics in my backyard now. The plan is to get the ibc system running again at home as a herb-garden for the Mrs. But I'd also like to run a decent sized system to grow veggies for the family (3 kids).

Wow this is becoming long-winded. Sorry. I'll try to get to the point.

In Tassie we are restricted to triploid rainbow trout as the only eating species we can grow. I know another user that no longer posts on here got permission from IFS (Inland Fisheries Service, the government body that controls all fresh water bodies in Tasmania, including home aquaria!) to keep native Blackfish but I'm not holding my breath on that one.

My main concern I guess is with water temperature. Tasmania is cold for much of the year and water temps are often below the optimum growing conditions for trout. My plan for this is to use a greenhouse or poly tunnel to get things nice and warm during the cooler months.

But what I can't wrap my head around is keeping the water cool when the temperatures rise. A local system I saw had trout in a partially sunken bath tub and shaded for much of the day, and he was still having to harvest early and only getting 9 months of growing time maximum. I'd like to be able to grow the fish just a little bigger if possible.

Have any experienced users got any suggestions for water-cooling or discharging heat from the system?

My ideas so far include keeping the fish in a deep pondlined pit in a shady spot with an insulated lid - but that doesn't help with the grow beds acting as giant heat traps. Ideas please!

A water chiller sized appropriately for your system will work. I've run one on my larger system (9500 litre FT) for a few summers.

How economical do you find them? Also Is that something I can diy or is it better to purchase something? Thanks mate.

Sent from my ONEPLUS A5010 using Tapatalk

Most aquarium/aquaponics stores will have them. You can't really DIY effectively unless you have a very small system.

Mine is quite economical, since it runs almost entirely on off-grid solar power. How much energy it uses depends on how efficient it is, and what its capacity is. Mine is a very efficient unit, but I suspect way oversized for what you want - 2kW operating power, with typically 4-6kW of cooling, depending on the ambient temperature

Hi Grubb,
Good luck with setting up the system when you finally get it home. I have 2 systems outdoors running silver perch and am currently building a greenhouse with another 2 systems to keep SPs growing through winter. This will leave one system outdoors which I was also considering keeping for trout. All of my systems are DIY 12V solar (except my air pump is on 240 V with 12V backup). My grow beds are 3.6m x 1.2m and high temps have been my major concern. My main outdoor set up has a very well insulated and shaded FT sunk into the ground, as is the sump, but heat has still been a problem. To combat it, I use evaporative cooling....hoops over the GBs with a thick cotton (king size mattress topper covers) and mist spray nozzles on a timer underneath. The covers are open ended so air can flow through to assist with evaporation. My highest water temps have been 28C, which is still too high for trout over the summer here, but may be OK for Tassie if you don't get that high. Evap. cooling will work well in Tas too. In my greenhouse, I will leave an IBC in the shade and insulated as a reserve exchange water source if temps get too high. I will also be running fog misters and fans (again 12v) to assist with cooling, but trout will certainly be impossible in these systems.
In your case, I think I would run an outdoor system only and not worry about the greenhouse. Most herbs will still grow well enough unless you want turmeric/ginger etc (maybe you could have a small GH over one GB if you wanted these).
Good luck with your system once you get it set up.

Anyone has seen this system? https://www.thesprucepets.com/diy-do-it ... er-2924600

It will work just fine if you have a small indoor fishtank. A bar fridge, or even a regular household fridge, just doesn't have enough capacity to keep the water in a large outdoor system cool enough for trout in hot summer weather.