Size of tank in gallons or litres.
How many fish and which type.
Water stats in ammonia,nitrite,nitrate,and ph.
Need to look if the fins been caused by nipping.
Any white edges or red, or red streaking in the fins.
Nitrite should be 0.
Strange that the nitrate is 0, whats your tap reading in nitrate.
Would of like to see how many fish were in the tank.
I would add interpet anti fungus and finrot med.