keep your reservoir temps from getting too warm, and aerate 24/7 ... occasionally, during reservoir changes, I'll dose plain water with some hydrogen peroxide (cup per gallon), and run the system for a couple hours, flush, and refill with my typical solution ... REMEMBER: the hydrogen peroxide will also kill off your beneficial bacteria, so, after flushing the peroxide out, you will want to replace those organisms ... I use Fox Farm 'Big Bloom', it's a worm-casting tea, etc., that will fix ya up :thumbsup: