I have been cycling my 55 gallon tank and for the past 4 weeks or so I have been getting a consistant reading of 0.25 ammonia even though I was past the time that everyone else says it takes to cycle a tank. This morning I tested and it was 0.25 again. I did appox a 40 percent water change then a few hours later tested again and it was still at 0.25. I have been using a Red Sea test kit but last week purchased an API ammonia test kit so I decided to check the results with that. The API is showing a very definite 0 for ammonia. Has anyone else ever had discrepancies between brands of test kits or know anything about one being more accurate than the another?