How to clean tank....

I have a 47gallon bow front and been running maybe 6 months. Had a potter angle, blue eye cardnals, red spot cardnals, cleaner shrimp, fire fish, a clown and a goby. All seemed well. About two months ago I add two corals-sorry don't remember there names-and a marine betta. Now everything is dead but the corals, cleaner shrimp, and betta. Any ideas as to what happened? How can I correct my tank so it stops killing fish? Pulled Betta out.

 

Need way more info. What are your water parameters? If all you did diff was add a couple corals I highly doubt that had anything to do with the fish dieing.

 

That really is all I did. My nitrate leaves have been on the high side.

 

What are your water parameters?

 

I am new to the hobby so I am not sure what exactly you need.

 

Parameters include:
Nitrate
Nitrite
Ammonia
pH
Alkalinity
Salinity
Temp

Optional:
Phosphate

 

If your not regularly checking these things then that is most likely the problem.

Bill

 

If you got to a fish store like Sea of Marvels, Pets Playhouse, Coralville Bay (are these still all going?) they will test your water for you. You'll want to get some test kits though.