Help Mad Silvers

[hupnupnee]

Hi there,

I put some 6" silvers into my new system about 1 week ago. They where fine for the first few days and then on day 7 one of them started to go beserk! It would dart around the tank and crash into the walls, then try to swim up and out of the water. It would then get tired of this and then sink to the bottom and lay on its side for while. It would then repeat the whole thing again. I did a half water change and it perked up a bit but then died over night. I now have another two fish behaving in the same way. I changed another half of the water. I have tested pH 7.2, Nitrite <o.o18mg and Nitrate <0.2mg and phosphate 0.01mg. I had 12 fish in 750l an airator. The water passes through a biofilter (plastic balls and filter cotton) the cleaned water cascades into the tank to add additional oxygen.

Has anyone got any ideas about what is going on and what I can do about it.

Thanks
Tim

[Mantis]

Where did you get the water from to put in your system?

[Erich]

my barra did the same with different PH levels when I added water

[RupertofOZ]

What's your ammonia level!!!!

12 x 6" Silvers in 750L.... with a few bio-balls (unknown amount) as a filter...

I'd take a punt that your fish are "burning" in ammonia...

[Murray]

Yes, my best guess is similar to Rupert's.
No Ammonia test results ???
No grow beds ?

[hupnupnee]

Thanks so far everyone,

I thought ammonia might be the prob, don't have an ammonia test kit yet.

But

it has only affected the three fish no others seem affected at all, the fish have not eaten at all since I got them. I had a 9l bucket of bio balls which has been increased to about 30l plus about 10l of fibre. The water was sourced from my gal rain water tank. pH about 7. I innoculated the water with a few buckets of water from a tank I was keeping a carp in as well.

Are these normal teething problems?

Cheers

[hupnupnee]

Bought an ammonia test kit today, the readings today are
NH 0.5
pH 7.3
Nitrite 0.033
Nitrate 0.14

What do ya reckon?

[RupertofOZ]

Have you got the tank covered, or in darkness... then startling them when you raise the cover/expose them to light??

[dbird]

I suspect the that the water from a galvanized tank might have something to do with it.I had some go much the same way and they were in water from a galvanised tank.
Cheers ,Don.

[dbird]

A week is a long time some times .I am not so sure about the gal.tank now as I have got a new lot of trout and they started doing the same thing but this tank is fibreglass.I lost 15 out of fifty six .They came from a small lake that was fairly salt so put some salt in the tank and they started to improve almost strait away.I haven't lost any for four days now and they are all feeding very well generally look prety happy.The temp was 12c,ph 6.5 and all the other factors were well within limits.so I don't really know what the problem was.
Cheers Don.