My Tank currently: 50 Gallon Planted Tank of RO water 2 Sunset Gourami 7 Neon Tetra 1 Ember Tetra 1 White Molly 1 Black Molly 3 Amano Shrimp Parameter: Tested with API Test Kit & Seachem Nitrate & Nitrite Ammonia: 0 Nitrite: 0 Nitrate: 40ppm Ph: 7.1 Doses: 1 once every 2 Days Co2 1 bubble every 3 seconds Seachem Iron Seachem Potassium Seachem Flourish Seachem Flourish Advance Seachem Equilibrium Filter: 2 API 30 Gallon Filter both with an Aquaclear Sponge, Pothos and Peace lily plant inside, a filter pad, and ceramic rings. Hey everyone, so some time ago I accidentally made the mistake of dosing Seachem Nitrogen in a 2-week span as I thought my plants were lacking and having insufficient Nitrogen as their leaves were yellowing. I only dose twice at the minimal as I wanted to see if it even had an effect. At the same time, college was in full swing for the upcoming final exam (It was ) so I didn't pay much attention to the water chemistry and such until one day. One of my ember tetras died, too busy with the exam, I thought it was just natural causes. The next day, another ember tetra died. Concerned, I did a water test with the API test kit and found that Nitrate was through the roof over 160ppm! A couple of things to note: - I use RO water and here it's a task so it takes at least 1 week to have bottles ready to be poured and refill the tank. I also tested just to be sure if it's my water that's making this mess and thankfully it wasn't. - I feed my fish with two scoops flakes with those sea monkey spoons I have in order to measure the amount of food I put into the tank. Along with bloodworms once a week and 1 scoop of pellets on certain days. Fasting is on Sunday. And peas on certain days I don't remember how my water change went but over 2-3 months, I did at least (3) 90% water change. At the beginning of the problem, Nitrate was still over the roof despite some decent water change; one being a 90%. Near the end, I got it down to a 20ppm. Over the entire course, I invested got a small portion of Seachem De*nitrate from a friend. Turns out it takes time and the right condition which I didn't have. I bought API Nitra-Zorb after reading here on Fishlore and other reviews that it helps. For some reason, it didn't for me, even after a recharge. After all of this, it finally brought me here today. I just got Seachem Nitrate/Nitrite test kits as I read that there is a chance my API test kit may be off after over a year of using the same old bottle. And got a reading of 40ppm. I have no idea what is going on but despite this high nitrate reading, throughout this entire time, my fish are swimming and acting completely normal. No deaths, no swimming near the surface, no erratic swimming, no loss of color, nothing. Some brown algae but that's it. This has never happened to me before and if I ever did had a high nitrate reading, one water change should be able to get rid of it completely as it has before in my experience so far. I'm not feeling comfortable having high nitrates sitting in my tank so any help would definitely be appreciated. Chemicals, method, whatever. Thanks in advance.