I've used everything in the market except for rowalith (no deltec reactor ehre) and koralith. Ultimately they were all the same except for 2 things: PO4 content and cost. If you run a little PO4 remover, the issue number 1 is mute. FL crushed coral has the highest amount of PO4, at least that I found. However, schuran media is not that far behind. Next time around, I am going back to the crushed coral.