I just got a new 150g and im debating on what substrate to use. I have a 110g with 1" 1.5" black rocks as sub. It makes it real easy to vacuum all the crap on the bottom. I was thinking about black sand or small gravel for the 150g but im going to have a lot of fish. I don't know much about cleaning sand and gravel tanks but i would imagine vacuuming it would be a real pain. is it ? and how else would your clean the sand.