#ed_op#DIV#ed_cl#Hey guys, I've been checking out your site, real nice. I'll start off by apologizing for what I think is going to be a long post. I've had a 44 gal. hex fish/reef tank for a little over 4 yrs. now. The only way I've learned things other than researching on the web, is by trying and usually failing. First off my nitrates have read between 25-40 ppm for over a year. ammonia 0, nitrite 0, ph 8.3, everything else is fine. For filtration I have a wet/dry filter with bio-balls and a red sea hang on skimmer. I've allways heard bad things about bio-balls so I've tried to clean them about once a month a little at a time as to not shock the tank.Also I've used store bought distilled water for water changes etc., which I have tested for nitrates and it reads 0? But could this still be a problem?I've ordered a ro/di machine so maybe it will help. And by looking around on this site I found that I've been doing one of the dumbest things; my sandbed is about 3 inches thick, well once a month when I would do a water change I would vacuum all the way through the sandbed, thinking "man how does this sand get so dirty?" So I guess I've been removing alot if not all my good bacteria, could this be a cause of my nitrate problem? I would appreciate any advice? Do I need to remove the bio-balls? Do I need a refugium? and what is one? Thanks for taking the time to read this, I'm charging my batteries for my camera so I'll post some pics of my setup in a few hours.#ed_op#/DIV#ed_cl#