Backyard Aquaponics
A place to discuss aquaponics

Checked the silver tank on sunday & found 2 dead fish. 3 more dead uptil today.
fish all look in good condition (except for being dead) no visible signs of any thing at all.
Silvers were 40mm long in november when they were put in the system (now 60mm to 80mm long)
water tests are all normal
pH 6.4
ammonia 0
nitrite 0

The trout (same system different tank) & goldfish in the same tank all seem fine as do the remaining silvers.
Can anyone offer any suggestions.

Maybe water temp, trout and goldfish will handle lower temps than silvers.

What is your water temp?

Sorry to hear toddscat.

Can you post a pic of them?

Hows your air situation?

water temps today 9-10 degrees, it has been quite mild here for the last week or so

sorry, the chooks got the dead fish. will take photo of the next one to drop off the perch. The tank is timed flood & drain 15 on 30 off with water spraying back into the tank as well as the drain from the grow bed (no additional oxygen)
The fishes mouths were open.
If it were oxygen related wouldn't the deaths occur on mass rather than slowly over 4 or 5 days?

I don't know much about Silvers, but I would have thought Trout would have been dropping off with lack of oxygen before Silvers.

Which tank is the water spraying back into

good point Arbe.

Temp is ok, should be plenty of air, PH and nitri are ok. Any rain recently? Run off from something toxic? Although you would think others would be affected also. Silvers are pretty hardy so not sure, if there was a problem you would think the trout would drop first. Do you salt or have you salted?

water sprays back into the tank with the silvers

have salted approx 1-2 ppt maybe 3 or 4 weeks ago

You will be lucky to get silvers that small through winter without extra heat whats the lowest tank temp [ealy morning]

Iv had very similar practices of late with my silvers...... (last 3 months)

Iv noticed they go off their feed, sort of float around the tank quitely then one or two will drop....

Last few weeks they have been much happier feeding well (iv got the tanks heated) very active around the tank etc.....

iv put it down to stress & Bullying.... as iv got mine in aquarium tanks i can see what go's on and iv noticed that 5-6 of the bigger ones really bully the others at times....

But Mouths wide open is one thing i was noticing... is there anything stressing them out??? Rapid fluctuation in temps or anything??

So really its a matter of wait & see. If they die they die if they survive, bonus.
What size do they need to be before its viable to get them through a melbourne winter

Jamey.. I cant see what would be stressing them. There were 30 silvers & 2 larger goldfish in the tank. The tank is outside open to the weather, so the temp will fluctuate with the weather but as stated earlier it has been mild for the last week & it hasn't had any problems before when it was cooler.