My main advice is to rinse the flourite really well. I love mine but all the dust in it took several days to settle in my tank.
As for you main question I have flourite dark on top of flourite regular in my tank - I like the dark colour better and didn't mix it with anything.
29G - ReefKeeper Lite Controller - Pressurized CO2 - Hydor Inline heater - Fluval 205 - Fluval Pimp #18
Last edited by Landau; 01-13-2011 at 04:29 AM.