I am very new to aquariums and though I have the best intentions, I don't understand a lot of what's happening in my tank. I've had a group of 5 tiger barbs for about 5 weeks now. I've had a couple die and I have replaced them. Yesterday the fish we're fine so I did a scheduled regular water change of around 20%. The fish all started acting poorly. Hiding behind the filter and floating towards the top. I went and bought an API water testing kit and bought prime concentrated conditioner. After all the water tests the ammonia was high and so was the pH. I put in the prime and today one is dead and the rest are not looking too hot. I again did the water tests and found nitrite 0, ammonia 1ppm, PH high 7.4 and PH 7.6. I am lost as to what I need to do. I added more prime and I'm about to just forget this whole thing and throw a goldfish in a bowl (as they seem to live years that way for me). Can anybody help me?