Backyard Aquaponics
A place to discuss aquaponics

I'd use much larger than 60l, the water temp will swing too much each day with such a small volume, and it may be too stressful for the trout. Otherwise it sounds OK, assuming you have enough filtration and water flow. What size will the trout be?

I have 3 IBC's next to each other, Sy1 FT, Sy2 FT and a water storage presently 40% full I could use that tank although I'm a bit worried I won't be able to catch them again at about 50 mm long. S'pose I could let the water out of the bottom.
What sort of filtration should I have for them?

Pete.

Since it is only for a week, much less than you'd need long term, but I'd probably use 100l or more of clay balls or gravel, and you'd want an established bacterial colony in it, as the little fish eat a lot for their size, and ammonia levels could quickly get out of control, particularly with warm water and high pH.

I was planning to harvest quite a few trout tonight, but after a hailstorm soaked the ground last night, today another heavy storm downpour when I was away flooded the area around the ST, and a lot of muddy water went in through thge gap around the SLO inlet, so FT and ST are full of muddy water. I think I'll leave it a while before harvesting any more, as I don't want muddy tasting trout, and hope the water temperature stays low enough for the trout.
I think I may have to dig in some sort of drainage system, as this is the 2nd time this has happened due to a storm downpour.

For a quick fix you could dig a hole or find a cavity where the water flow to and use a small bore hose to siphon over a long period of time or lower in a marine bilge pump with a float activation.

Pete.

" I use plastic bottles full of frozen saline water when transporting frozen food, particularly trout, as it melts at ~-20C and keeps the contents colder than regular water ice blocks."

Gordon should we be using saline ice blocks or containers in the FT on the hottest weeks?

Pete.

I can just dig a trench and lay some leaky ag pipe to drain the area around the ST. No need for pumps or unreliable syphons! However, first I think I'll squeeze something into the gap between the SLO and overflow prevention pipes and ST wall, so it restricts any water flow into the ST, which may be enough to prevent the problem, as accumulating water wont get as high as the ST rim before it drains away.

>> should we be using saline ice blocks or containers in the FT on the hottest weeks?

No, you aren't trying to cool your FT to -20C, you just want to cool it, so there is no advantage in having the ice melt at -20C instead of 0C, and (without looking up thermodynamic details) there is probably a little less total latent heat energy involved, so the same volume of saline ice wont cool the FT quite as much as fresh will, if starting from the same temperature.

Cool !

I harvested another 11 last night, largest was bang on 1000g, and the average was 714g, as I took a couple of smaller ones around 400g, instead of putting them back in.
36 left in the tank now but I'll take a few more out tomorrow.

The next 5 days are forecast to be low to mid 30sC, so I'll be keeping a close watch on the water temperature.

I've just noticed that I missed posting the last temperature graph I prepared, so here it is, while I work on the next one covering the past 3 weeks.

The water is warming up a fair bit in recent days to some warmer weather, 35C yesterday was the hottest it has been in many months.



We were away for last weekend, and with fairly warm weather forecast, I decided to drop in some ice before we left, just to be certain the water temps would stay in a suitable range for the trout. 23kg dropped the temps the expected half a degree, as can be seen here:

Only 28 left now, after taking another 8 out tonight. Average 590g, largest 848g.
The water temp is ratcheting up, with hot days and warm nights that don't allow the water to cool very much, so I've put the Air-cell surrounds around some GBs, and put some polyester insulation on top of parts of some of them to reduce the direct solar heating of the media. I've also started spraying the media with a fine mist of water a few times per day, to cool the warm media. The water reached a bit over 21C today, and I expect it may get a bit higher tomorrow and Wed before some slightly cooler air arrives.

I see a lot of Ozzy -ops having fish seasonally only...

Are no edible types available that can be used year-around?
[...I mean GOOD eatable fish, not just barely edible]

thjakits

Depending on where you are in the country, you can grow all of these year-round: trout, bass, various perch, catfish, barramundi, eels etc. I have trout year-round here with a chiller- see my other system thread.

What is the situation with Tilapia in Oz?