I think my fish r sick

[Jordan N.]

I would recommend a tank change in addition to the water change. ;) If you move some of that livestock into a tank that will accommodate their potential size more realistically you might find that water quality improves and both physical and psychological livestock stress decreases.

I absolutely agree --Bigger is always better!

If you can't upgrade then I recommend returning finding a new home for the tang and seahorse, the rest should be able to live quite happily in the current tank.

Edit: I should say that I recommend finding a new home for the seahorse either way --They just aren't suited to a community tank. Or you could upgrade and make the small tank a Seahorse species tank.
-Jordan N.