cherisec
Aquarium Advice Apprentice
Hello. I have a 15 gallon tank and I'm having a massive problem with extremely high nitrate levels (over 250mg/L). Currently, my tank runs at about 25-30°C with it being summer here, I have a fan cooler running. I currently have 3 platys, 2 danios, 3 snails and a plec in my tank. I have about 5 or 6 plants too. I had about 7 platys and 6 danios before but they all started dying. I tested the water and noticed very high ammonia levels (5mg/L) so I started treating for that with Ammosafe and the current ammonia level is 0.25mg/L. I do 20% water changes about 3 times a week but it hasn't made the slightest dent in the nitrate levels. I just use filter sponge in my filtration system and I cleaned out the whole filtration system about a month ago. My tank has been established for more than 3 years and I've never had this problem before.