Heya. I did a freshwater test of my tank and stand last night. The tank is glass, 60x18x20. I had to shim the bottom since it's on a tile floor. Before filling with ro/di water, I used bubble levels (one four foot long, one 8 inches long) to ensure it was level both lengthwise as well as front-to-back.

It is mostly filled now, about an inch below where the final waterline will be. Problem is: it appears that a 1/8" unlevel-ness developed during the filling of the tank, in the lengthwise direction. That is about 3mm.

Is 1/8" over a 60" length unacceptable? Or is it: might work, but is not worth risking? Or is it: I'm being overly paranoid?

Thanks for any advice/experience you care to give. ..Karl