angel problems

[hadvisor]

A couple of weeks ago I introduced a couple of new baby angels - one died right away and then a gourami and one of my huge angels died. I medicated the tank with some clout tablets per gallon recommendation - all seemed ok - my big angel had the flicks and whatnot - did not do much but just hang out by the intake tube. He pretty much started to act somewhat normal. Beginning of the week both full size angels started to develop some type of white buildup on their rear fins - fins seem to be getting shorter in places - cotton like buildup. All other fish in the 46 gallon seem ok at this point - water parameters are ok-the little quarter size angel is doing great. I never really had any type of disease before - I dont want to lose my big angels. Any help would be greatly appretiated on medication recommendations. Oh ya, I have been keeping the water pretty clean with large changes more frequently - I have been keeping the temp pretty normal - cleaned the gravel a little bit more than normal after this all came up..

 

[Allivymar]

Sounds like a bacterial infection.

I'd isolate the fish affected, and use a broad spectrum antibiotic such as Kanacyn.

And what are the water parameters? Even with lots of water changes, there can be nitrogenous waste issue, especially with new additions.