I recently had an issue in my tank with ich. So I used salt and heat treatment for a couple of weeks and got rid of it. I have spent this past week lowering temperature back down. The ammonia, nitrite and nitrate stayed good through the whole process. The salt treatment ended last Saturday and I have spent this week lowering temps and doing smaller water changes to get rid of the salt. Everything was fine until this evening when I checked everything out again. This time I had an ammonia reading of 25ppm, 0 nitrites and my nitrates had raised from the usual 10ppm to 20 ppm..I did water changes of about 12 gallon to lower it and when I rechecked the numbers, the ammonia was still at 25ppm and nitrite 0, but now I am getting a 0 reading for nitrates also! What could have happened?? I am so confused. Please help! Have I lost my cycle again? I don't think my fish can survive another cycle. What can I do??