Help Please

[Shimano]

nitrate 0-20, nitrite 0, hardness soft, ammonia 0-.25, ph is somewhere between 7.6-7.8. Those are the parameters for my tank. I have lost 3 fish in the past two days. What seems to happen is that they start to breathe heavy and become less active. Is weird because them seem to swim fine for awhile then just drop to the bottom. There are no visible spots or anything. Its seems to only be affecting a few at a time. I just hope I don't lose all of my fish. Any ideas?

 

[Devilishturtles]

Are these fish new? What kind of fish are they? How old is your tank? Is there any way a contaminant could have gotten in?

 

[black hills tj]

I've heard that even trace amounts of ammonia can cause chaos in a tnak.

 

[Shimano]

The tank is about 2 months old or so. The only new fish are the redtail sharks, but I have had them for about 2 weeks now. I have 3 tiger barbs, 2 silver tip sharks, 3 red tail sharks, one black molly, 1 fancy guppy, and 2 orange platies. I don't think anything got in there because the lids are shut. I did a water change on saturday. Other than that I have no idea.

 

[Jchillin]

Which of these fish have expired?

 

[Shimano]

One Black molly has died, one tiger barb, and one silver tipped shark. The numbers i posted above are the numbers after these guys had died.

 

[Jchillin]

Ok, the small ammonia spike is not uncommon after fish deaths. IMO, all signs are pointing to problems with the addition of the red tails combined with the Silver tips. What size tank are we talking about?

 

[neilanh]

How big was the PWC you did, and what type of dechlorinator are you using, and how much?

 

[Shimano]

Its a 55 gallon, i did about a 15 gallon PWC. And i added 15ml of API stress coat. becayse it says to use 10 ml per 10 gallons.