Backyard Aquaponics
A place to discuss aquaponics

After a very wet June, 220mm, July has turned fairly damp too, it's been drizzle and fog all day today, just getting up to 6C late this afternoon, so the water temp is on the way down again. The 139 trout have been eating about 200g of 6mm pellets per day.

The water is getting quite warm for July, thanks to unseasonably warm weather. The fish continue to eat 200 or 300g of pellets most days.
There is still a steady supply of capsicums ripening, which is surprising for this time of year. I've pulled out all the basil and most tomato plants, and there are a few other things that need to come out soon in a major clean-up, so some brassicas can go in, along with some turmeric, most of which sold very well at the markets.

The water has cooled down again after the very warm weather of mid-July.



I syphoned out a lot of fish poo from the ST this afternoon, something I hadn't done in a long time, and there was a lot of it! I think it was quite anaerobic under some of the thicker deposits, as lots of bubbles rose to the surface when it was disturbed by the hose. I refilled the sump afterwards, which should have oxygenated the water quite well.

I'm still getting a reasonable supply of capsicums, which is surprising for this time of year, but a lot of the other plants have died off and been removed, so I have a few GBs that need planting out soon.

Howdy. Those are unusual weather swings for your area, are they not? Does it ever freeze? The reason I ask is I know you have a chiller, do you ever need to warm the water? Our weather has been rainy these past weeks. The spa conversion to Koi pond hasn't warmed up since we put them outside. Our temperatures are swinging wildly. We're seeing 40 degree swings daily. With climate change it is getting hard to do any growing outside. We may need to expand our greenhouse... Didn't mention it to the Wife yet Anywho, I'm looking at inline water heaters. Thinking about heat exchangers, perhaps building a solar heat exchanger, that sort of thing. I respect and in awe of your knowledge and experience, ideas?

Wide diurnal temperature range is fairly common here, but getting to over 20C in July is rare. Yes we get plenty of frosts, any time the screen temp is below about 4 or 5C there is frost on the ground, and the screen temp gets below zero a few times per year, but nowhere near as often as 20 years ago, when frosty nights were much colder. Being on the side of a hill means its 2-4C warmer than down at the front gate on cold nights.

I could do with a bit of water heating in winter, but it isn't that much of a concern, as the trout just eat less than usual. It's really only a few days per year that it stops them eating at all, so I've got no plans to spend any money on water heating at this stage.

If you want to heat water in winter I'd suggest heating in a way that adds heat to the system overnight, rather than during the day, otherwise you will increase the diurnal range of the water temps, which isn't a good thing. So if you are doing it with solar energy, heat a tank of water during the day, and transfer that heat to the FT during the night, either directly if no toxic metal concerns (Copper etc), or via a heat exchanger.

Thank you for the reply. Good point on the temperature swings during a 24 hour period. I'm thinking perhaps a timed inline water heater for the Koi tank. It is good to know that it needs to happen at night only. I believe the consensus or heating Koi ponds is split. Letting it freeze over isn't good for the fish, but yes they'll go somewhat dormant in Winter. I just want to keep a clear place on top with oxygen and hopefully depending on what this Winter brings I'll be able to keep the whole pond somewhere between 10°C to 15°C. Who knows if I can do it. It's a worthy dream.

You'll need to have a cover, preferably insulated, over the tank to slow the loss of heat, but in any case, it will use a lot of energy to keep the temperature up in your winter weather conditions.

The water is staying warm enough for the trout to be hungry, currently they are eating 300-550g per day between the 139 fish in this system, so they'll each be adding about 3g per day on average.



There will be a stack of small yellow capsicums ready soon, but there is lots of empy GB space ATM. I have some Roma and Grosse Lisse tomatoes and other seedlings ready to plant in the next few days.

A couple of pics, GB#9 outside the GH, with garlic, peas (need to put in some supports) and some beetroot and chard




Newly planted (yesterday) tomatoes with supports, with some marigolds in between

Where did you get those triangle tomato supporters Gordon?

My wife found them on the specials table in Bunnings, about 3 months ago.

Warm weather followed by some cooler days, but not too much variation in the water temps, although it might cool down a bit over the next few days.

I will be looking next time I am there. They look to be a good solution

The ST underwater worm farm in action! There are hundreds of them in there.

I harvested 17 trout last night, the largest 2 were 721 and 722g, smallest 394g, average 485g.
I've only got 1 left in the fridge, my wife took the rest to give to friends and sell a few to some cat owners she knows - "dolphin friendly cat food" is quite popular