Leveling a Tank

[rastaangel]

It was out by 1/8" from the shim compressing BUT the place that built the tank also used a peice of glass with a huge shell on the bottom which they shouldnt have which is were it cracked... So if the bottom wasnt a bad peice it may not have happened, but I take no chances.
I first level with a stanley fat max level to get it close, they claim there accurate to .5mm but I dont trust them that much