Yes, there is a slight diatom problem... very little cyano though. I haven't had any breakouts on the cyano as I'm using RO/DI water, and doing w/c's everyweek. I'm going to be getting pods in there to help with the diatoms, and hopefully I'll have some bristleworms in there as well. Starting with dry rock is the way to go, but building the fauna up is difficult!