HELP!!! Ammonia detected after TSS!!!?

I have a 30 Gallon Eclipse Pfe 3 tank w/ filter, bio wheel, and heater. My tank has gravel and fake plants. I started the tank up on July 6th with nothing in it. A week later I added 4 tiger barbs. ammonia, nitrite and Nitrates stayed at 0. Then I added Tetra Safestart On July 22nd (this past Thur) and immediately put in 2 more tiger barbs and 4 blue/green tiger barbs. Two days later I got an ammonia reading of 0.25ppm. Nervous about that, since my pH in the tank for some reason stays at 8.0, I decided to do a 25% water change. This was last night. This morning the ammonia reading is still 0.25ppm, while my nitrites and nitrates are still at 0ppm. Did I mess things up by doing the 25% water change?? I just got so scared for the fish since I know the ammonia is more toxic in my tank with a ph of 8.0. I have another bottle of TSS (for 30 gallons) - should I add that one too, or is that too much? Or, should I just leave it all alone I find myself just constantly staring at them, hoping they are all fine. All of them are active. I have held off feeding them today, hoping to not make the ammonia levels worse. Does the ammonia level need to stay rised while the TSS is trying to cycle my tank?? Any advice would be great!! Thanks!!!