I re-read some of your threads and am amazed at the nitrate turnover in your reef with all of those fish. You have the microbiology down pat. My tank has been at a nitrate level of 30 with undetectable phosphate which is a common feature of zeovit converted established reef tanks. Phosphate limited reef tanks cannot reduce nitrate levels with bacterial activity. I'm trying NP Bacto Balance to get the bacterial activity increased with this additive. I'll let you know how it goes in a couple of weeks. Congrats on the article and thank you for posting your methodology.................Jim