So, i have been battling my 180 for the last two months. I cannot seem to get my Nitrates where they need to be. Some History: I have not been a water change type of guy. I know this can contribute but in the past I have always been able to keep it under control with a nitrate coil or bio-pellets. Lately, not so much. they have gotten as high as 50ppm but lately, seem stuck on 25ppm according to my salifert kit. even riht after a water change, I got 25ppm. same as I had before. I thought my salifert kit was bad, so i tested some freshly made up water. it tested at zero. I have done a 50 gallon water change this weekend and last weekend. and have not made an impact. (total water volume is in the 225 gallon range) I am running about 1500Ml brs biopellets I setup an ATS about 5 weeks ago. I am getting a good strong growth on it now and feel it should really kick in soon. FWIW, my Alk is 7.8, Ca is 450, Ph is 8.0, phos is .03 any additional suggestions? I lost two very large colonies to my issues. they went up in massive RTN events likely due to sustained exposure to the >25ppm Nitrates.