The simmer doesn't foam up.
Great! The idiot handyman I hired to move the tank claimed he had a volume calculator and estimated my tank to be 380 gallons. I just went to reef central and discovered their calculator that estimates the tank at 497 gallons! That's a huge difference but sounds more accurate.
Oh, that's outside, very general measurements. I personally don't think it matters that much. It just means I have to buy more sand to get the depth I'm looking for.