Whoa..Clove Oil
Something is not making sense here. Clove Oil is an anesthetic when given to fish, it is also used for euthanizing fish with terminal disease. It is certainly not a cure for anything.
With water changes every five days, I don't see a correlation between disease and water changes, the time frame is too small.
I'm speculating here but it could be an osmotic problem, temperature shock?, unconditioned water? Radical pH/GH change etc.
I think we should explore the bio-load / osmotic angle
That would fit the symptoms you describe.
You still have not given us a set of tank parameters to work with.
Regards.
Jay