Hello, i have had for and reef tank for about 15 years. Mostly success. Recently my nitrate have gone sky high. 200 plus... i change ro water every week 10-20%. The ro source read zero nitrates. but can't get the tanks numbers to come down. using posban, ploy ball reactor and good skimmer... feed once per day. i get the hing number in all 3 tanks. ( 30 gal fresh water)... about to break it all down and start over.




