Gave Rosy Reds Now All Fish Dead

[smashley]

I work at a fish store but I have never heard of this happening before. WE NEED HELP! My boyfriend has a 150 gallon tank with 4 huge tinfoil barbs, 2 big bala sharks, 3 leporinus, pleco, ropefish, dinosaur eel, talking doradid catfish and an albino channel cat. Last night he bought 3 dozen rosy red feeders (the usually get 2 dozen every week or two) this morning he woke up and almost all fish were dead, all the big fish eaters were dead and the rest were dying. The fish had cloudy eyes and chunnks of there skin was falling off, not just a the scales but whole chunks of the skin was falling right off, the fins were white and frayed and looked like they were rotting. This all happened in 7 hours. What could have caused this so suddenly? The feeders at the store are still alive and don't appear ill in any way. Most of the fish were about 5 years old and had been very healthy, the water was tested at the same time the rosy reds were added and all was normal. None of us know what to, us being my boyfriend, my manager or myself. Please give us some advice!

 

[three-fingers]

And that is why feeder fish are a bad idea, read this: http/www.fishforums.net/index.php?showtopic=148384 .

Can you get water stats?
How often are water changes done?
What kind of filteration does the tank have?
Can you provide pictures of some of the ill fish?

You probably already know that the 150gal isn't suitable long term for all of those fish....
Best thing you can do right now is lots of water changes (plus quarantining then re homing any healthy fish) until you can work out exactly what happened, but it sounds like it's just the result of lots of factors that have built up.

 

[smashley]

Stats from last night were a little off from usual, but had been similar all week:
ph 6.5(normal ph in the tank)
kh was at 0
gh 30
no3 15
no2 .5
nh3/nh4 .75

today nitrate, nitrite an ammonia were off the charts even after a 75% water change but the ph and hardesses were still the same

He does water changes every other week, just under 50% i think. And he runs a fluval fx5 just cleaned and medias replaced less than 1 week ago.

It is a lot of fish for one tank but not all were even close to full grown yet. Normally there are no problems with no3, no2 or nh3/4 going above VERY low levels if not staying right at 0

It boggles my mind that it went from slightly off to VERY VERY BAD with 10+ dead fish in so few hours. If it were my tank I wouldn't have added feeders if any stats were out of whack.