One of my rosy reds is looking a bit pale and kinda staying near the top. I did a partial water change and cleaned the filter. Also, I added some anti-bacterial stuff called mela-fix just to be safe. Any idea as to what could be causing this?

It's hard to say. How long have you had the rosy red? What other fish and animals do you have in your tank? Do they seem normal? How big is the tank? Have any recent changes been made? Did you test the pH, hardness, ammonia, and nitrite to be sure they were ok? How much and how often do you change the water? What is the temperature? What do you feed the fish? What kind of aeration and filtration do you have? All of these questions will help me to help you and your fish.

In general, when fish are under the weather (and washing out or turning pale can indicate that as well as other things such as simply trying to match the background), you can treat the tank with aquarium salt at a tablespoon per 5 gallons for most fish (more for certain fish) and MelaFix. You add the MelaFix and did a partial water change which would have been my main suggestions. Look into the other things I asked about to be sure everything else is ok.

I have a small section on washed out fish here:
http://www.fishpondinfo.com/health3.htm#wash

Rosy reds can change color some but if the fish has really gone pale, it usually means something is wrong. Good luck!