Hi...

If you are looking for information on saltwater tanks, then you should probably post in the General Marine section of Aquaria Central.

Roan

Cichlids provide a lot of color in a freshwater tank. They do tend to be aggressive, though, so your current stock would probably have to go. You also need to be careful of size, but you should have plenty of options. I had a labidochromis ceruleus (sp?) that was pretty mild tempered and was a very beautiful bright yellow. For the most part, he got along with community fish, though he did make a snack of one occassionally.

Rainbows are very colorful ! But you would have to get rid of the goldfish and possibly the shark if you were to get some of those. Goldfish aren't a good fish to mix with tropical fish as they are a coldwater fish. The temps you need for tropicals are really too warm for goldfish.

I would suggest some rainbows and possibly blue rams. RoanArt has lots of information on rainbowfish if you want to check with her on types and how many should you choose those.

Congo tetras are also a very nicely colored freshwater fish...and one of the larger sized tetras, so they wouldn't get lost in your 55.

Here's a pic of a very colorful german blue ram.....Roan has some nice pics of her rainbows as well if you want to chase her down and ask her about them....