Red tailed shark dying

Question
what can i do to save my red tailed shark ? he is having problems swimming keeping afloat as he is getting pushed around by the current and keeps getting sucked into the filter we just got him from the pet store a couple hours ago and we ran our tank for two days the temp is 80 and ph is 6.5 the nitrate is 0 ammonium is 0 nitrite 0 I also bought two cherry barbs and a bristlenose pleco which are all doing fine please help to figure out whats wrong so maybe i can save him

thanks allison

Answer
Hi Allison,
I'm afraid that by the time I have answered this it may be too late for your red-tail shark. It sounds like you just got a weak individual whom has been stressed too much by petstore life and the transfer from the petstore to your aquarium was too much for him to handle. Some fish are stronger than others.

One thing you need to be careful of -- is your aquarium is a recent setup and it likely has not had time for a 'biofilter' to get established well enough to handle a tankful of fish. So please try not to stock your aquarium with anymore fish for at least several weeks to avoid overwhelming the weak 'biofilter' and causing the fish severe stress and illness.

The biofilter is beneficial 'good' bacteria that colonize your gravel and filter bed and all other surfaces in your aquarium. They get rid of fish waste in a simple process. First, one type of bacteria develop and convert ammonia (produced by the fish) into nitrite....Then later, another type of bacteria develop to convert the 'nitrite' into nitrate... the final end product which is harmless. Ammonia and nitrite are both harmful, while nitrate is safe unless in very high amounts.

Just give your aquarium a few weeks at least and test the water to make sure it is safe before adding anymore fish. Safe levels would be ZERO ammonia and nitrite.

I hope this helps and best of luck!
Karen~