Need help with DIY sump stand

[ReefDreamz]

I built a stand for my sump using a 2x4 frame, a 3/4" plywood top and 1/4" PVC board over the plywood. I made sure everything was level. It came out great. But when I set the sump on the stand I noticed the front left corner of the sump was not in contact with the stand surface. After partially disassembling the stand I found that the problem was that there is a very slight hump in the front face 2x4 which is causing a teeter-totter effect. If I raise up this corner of the stand then the front right corner of the sump is not in contact with the stand. I dont really want to go down the road of trying to plane the 2x4s or shim it because I will never get the surface completely 100% laser flat using dimensional lumber and plywood. Can I use foam under the sump to correct this? Foam like this: https://www.thefoamfactory.com/closedcellfoam/polyethylene-foam-roll.html. The 4 lb one is what Tidal Gardens uses under their aquariums.

 

[blaxsun]

Yes. I mean, short of planing, sanding or shimming - you don't have a lot of other options available. Could you possibly reposition the sump at all, ie: move it a few inches over to the right?

 

[CoralB]

Absolutely!!! . As long as the sump and the stand is close to being square , plumb, and level , foam is the best way to go . I always use foam for aquariums and sumps to keep them from having any undue unseen stress points that can cause problems later down the road . I use 1/2” to 3/4” foam depending on the size of the tank . Good luck !!!