Thanks for the answers guys. ..i run rowa sometimes and was wondering if would been takin out my nitrates as well as i had 0 in tank and then i stopped rowa for a while and accorsing to api test which i know is not the best (use salifert for rest havent had chance get one for nitrate) its 5.0 now and phosphates at .10 but i have some sps not doing well and others thriving ...some sps just seem to be expelling there zooanthelle while retaining polyp extension