Ok I have a little issue on my hands to say the least. I have used several methods of testing my water from, Red Sea, API and now salifert. I switch to salifert for the reviews and LFS opinions. I started to see a decline in my aquarium visibly after the first 90 days of switching. I relied on saliferts results to justify my maintenance needs I&E of water changes media replacement etc. I still had issues with my tank visibly but the test kits showed no signs of high nitrate, nitrite, ammonia, or phosphate. On the salifert test Nitrate never read about 5PPM. I then decided to try to match results with my API test kit and the nitrates had a difference of 20PPM between the two. I really don’t want to send off my water to get the true numbers and wanted some advice from the experience here in R2R. I have since done major water changes over the last two weeks and the API nitrate is show 10PPM and Salifert is 2 PPM. Which one do I trust. I am leaning towards API, since my tank is recovering.