I have been cycling my 72gal. fresh water tank for 3 weeks. I have the 20 gal. tank in there already(no room for both tanks), but I used the cycled water and the gravel in the wet/dry sump.Well the fish are fine, but the tank is not clear. Someone told me the overflow and wet/dry sump isn't enough and I need an undergravel system on a reef ready tank. My gravel is the fine type. Am I just still cycling :