Backyard Aquaponics
A place to discuss aquaponics

I have two tanks in the one system, both with silver perch in.

Up until about a week ago, both lots of silver perch were eating fine. Now the 14 silver perch in the smaller tank (600L) have not touched food for almost a week, while the 30 silver perch in the 1000L tank are chowing down like its their last meal.

The water flows from 1000L tank to 1200L of GB to 600L tank then back to 1000L tank. 1000L tank will have vol changed twice an hour, so 600L tank is having its water changed 3-4 time per hour (via SLO).

Water temps have risen lately to high teens, ph 6.8, 0 Ammonia, 0 Nitrates about 100ppm Nitrates.

Seems odd that one lot can go off the feed while the other have not. Any ideas? The ones of the feed are more mature larger fish so I thought perhaps spawning development (even though they wont in the tank) may be a factor?

I'm not overly concerned, though a little intrigued There are no signs of any disease on the fish and they are actively cruising around the tank and will rise to food when it first goes in the tank, but not eat it.

What temps are you getting in the sump, all seems a little odd though

Due to the degree of water mixing, the temps are pretty much the same, though you may be onto something that the sump will have a wider temperature fluctuation due to the water coming from the GBs.

Was 17 degs this morning, generally been between 16 and 18 whenever I've looked (measured in the 'sump'). I've not got a logger so only see the temps in the morning and evening.

They are probably worried about what your plans are with your new purchase.....

That's another possibility ArBe - new purchase has been located about 2m away from their home and plumbing has commenced. I'm not sure whether I'll be able to just drain off solids from the bottom everynow and then into WB. I'm plumbing it so I can do that or run it continuously through a RFF back to the sump...

Maybe they just want to be eaten?

Fish know best, eat and enjoy.

There was me thinking something was up and all they were doing was purging themselves for me!