Been busy and didn't get to do much. I thought everything was ok, but not so. I filled the 40 up with water and noticed it was way out of level. This is on a tile floor, that is over concrete and it used to be a garage years and years ago. So I didn't realize how uneven the floors were. So I removed all the tanks and shimmed the stand. This took me forever and I'm still not sure that it's right. It's completely level now all the way around, but I'm not sure my shim job is ok.I'll post some pics and maybe others can weigh in on it.
Also, the 40 gallon now touches the plywood top flush in all 4 corners, but there is still a slight gap in the center front and center of sides, but the corners are flush. I know the corners are what supports the tank, so I think I'm good, but unsure about it.
When I did a leak test, nothing budged on the stand or the tank and it was filled for over 24 hours. Just sort of nervous about it. I don't want to deal with leaks, cracks or anything like that.