Hi, I did a 10% water change Friday, on Saturday I noticed my fish had ammonia burns I did a 10% water change then a 40% water change. One Sunday I did a 50% water change and tested Ammonia levels and it was at an 8. I treated with amo-lock and Prime conditioner. Today I did a 50% water change and art the conditioner still no change. I have a 60 gallon tank with three medium goldfish, two very tiny goldfish, algae eater and some snails. I have an internal filter and the charcoal air water filter. Everything was fine and suddenly I had this spike in Ammonia. I have no missing it dead fish, no dead plants the only new thing is I tried a new fish food. Yesterday I gave them only a little bit of their old food.