Ok one day, then dead the next....

[gmwilsonuk]

I'm hoping someone on here can help me out.

A few weeks ago my 5-6inch Cobolt discus died. The day before when I watched them, it was fine, a little darker then usual but fine. I came home from work the next day and found it struggling to swim, Could only look upwards and had alot of dark Black spots on it. With slim in a few places. I could understand what it was. So I did a water change and raised the temp by two degrees.

I've noticed my Leopard has starting getting dark and has his stripes are visible almost all the time.

My tank: 150ltrs with 6 discus, 6 cardinals, 6 rummy nose, two plecs, 6 cories.
Water changes are done every second day at 20ltrs a time. 15ltrs r/o water, 5tap after 24hr stand.

Give or take below.

pH: 6.8 - 7.0
Nitrate: 0.0 - 0.1
Nitrite: 0.0
Temp: 30"

[Hollowman]

I would say your tank is well overstocked and you are not doing big enough water changes.

Have you added new fish recently?

[gmwilsonuk]

I've not added any new fish for over a year now. I've had the tank with the same livestock for at least 1.5 years now with out any problems, so I cant understand what it could be.

[Hollowman]

See the fish in my avatar.....it died, fine one day, dead the next. No symptoms, stress or signs. I put it down to a massive organ failure. It happens sometimes, it was painful as not only was it a lovely fish as part of a breeding pair, but very expensive too.

[lpiasente]

Six discus in a 150 litre :shock: . Not much swimming room for such big fish.

[Hollowman]

Six discus in a 150 litre :shock: . Not much swimming room for such big fish.

Is there an echo in here :D

[1fish2fish3fish]

answer is there in your own question.. 1.5 yrs with no problems.. ?
and now you have problems.. bigger fish, and less room, and they want to keep growing.. simple.. you will keep feeding them but mother nature finds it hard to get around the space.. so this leads sometimes to illness..
cards and rummies will get 1+ inches full grown.. Plecos, well 2 of them could total 30 inches + and dirty fish
how big are the plecos now.. bet they dont do much anymore ..just hide all the time.. thats a lot of fish for just the bottom of this tank size..
sorry for your loss
this tank size would hold 2 happy discus..