Hmm, well since I've been treating the tank with melafix, doing water changes and getting the parameters under control, their fins have been getting better. Infact my big plecos hole is almost healed right up, the other plecos rear fin is healed up, and my goldfish are getting better!

The big plecos color seems to be more consistant and not as dark now too. He got really really dark for a while.

So, we're getting there. They're all very happy now! Well, at least happier than they seemed before.