minimum 6-7polyp first reserve get the most possibly 8-10p if not more, have multiple plugs of this all loaded an at a great price and always a great seller, these are really bright REDS and BLUES, love light and waving flow, these easly get and are dime size heads with babys and some get size of nickel when happy enough, I grow these my self and do best around a 180-200 par that is where they are at now and thrive