Size of tank in gallons or litres.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.
What do you feed your fish.
Clear mucas poo can be internal parasites the signs are.
Long stringy white poo, or clear mucas poo.
Red inflamed anus or inlarged anus.
Worms prutruding from the anus.
Being skinny or bloated.
Sometimes bent spines.