iClear 30s on all of mine. I love these tanks! I just ordered an iClear X-1 and hoping I like it as well. IBTanks are awesome as well, definitely worth the investment. I've gone through a few tankfulls on mine and haven't even changed the carto yet. If I could I'd but all IBT but alas I cannot. The Aspire nautilus is great too...but I found it looks a little off on my MVP 2's. Too big.