I've had 2 tiger barbs in it for about 3 weeks now. (That's how long i've had the tank up and running too.) Last week I noticed one of the tiger barbs were getting pale, then really pale, I checked the amonia and it was a little high so I put reducer in until it was almost gone, but my fish still died about 2 days ago. My "healthy" fish now I can see has some ick on it. The ammonia is fine in the water. I'm not sure what the problem is but I think I need more than just one tiger barb. I did a water change about a week ago too. What should I do to fix these problems and when can I put more fish in it? Can I put 2 more fish in a tank with a fish that has ick or will it spread like flu?