As little as possible. :lol: No really, probably less than an inch. Just enough to cover the bottom of the tank but not enough to become a nutrient sink. I plan on vacuuming the sand bed at water changes.
Doesn't chew up the nut like channel locks either. BTW, I have no idea where to actually buy these things. He sold me this wrench from his spare tools for the shop. He said he had more so I didn't feel too bad. 
Haha. No seriously, there were a couple of reasons which were $$$, local availability, and it is my first large tank. I got quotes from Miracles and AGE but the freight was going to kill the budget since I live in the midwest. Also, my last tank was a sump-less 40g. I figured this tank would be a nice transition to a bigger tank with a sump and some extra toys. And I'd be able to set it up within 2 years vs 5. :lol: You are correct sir.
I really like this skimmer btw. The Askoll is extremely quiet, the Sicce pumps were not! It needs to be run in slightly lower water level, 6-8", ideally to be most efficient. I'm running in around 9-9.5" at the moment but could get it up to around 8" with how my stand is built. I'm going to see how it skims as is and decide if it's too wet once it starts actually skimming. If so I'll need to raise it a bit. Right now it ain't doing anything but foaming a little up the neck. Hasn't dumped into the collection cup yet. I wouldn't hesitate putting this skimmer on a larger system. I think it might be a little much for mine but I also don't really subscribe to over-skimmer either. :lol:
