I finally got a proper aquarium stand so that I could feel comfortable filling up my 40 gallon breeder stand all the way (adding an ATBA). Once it was assembled, though, I noticed that one corner of the stand is about 3/16 of an inch higher than one of the beams that meets it (pictures included below). All four corners of the tank are supported, and the sides are too; however, there was a gap between part of the front beam of the stand and the front beam of the tank, so I was worried about torsion. There's only one side of one corner that is higher than the beam that meets it, so I only have to correct half of one corner; however, since it affects one of the aquarium's longer edges, though, it's pretty worrisome.
I got some rubber floor mat material (about 1/4 inch thick and as dense as a yoga mat), which I cut to size to fit under the whole tank, hoping that the tank would compress the mat enough to eliminate the gap. (The mat is relatively thin, so it's nowhere near touching the glass bottom, which I know shouldn't bear weight). Once I placed the tank on top, I could still see about 1/16 of an inch of space between the tank's front edge and the crooked part of the stand's beam. The only thing I could find that would fit in that gap was some corrugated cardboard that Petco used to separate the pieces of the stand (not the box that it shipped in, which was twice as thick); I had belatedly read some reviews of the stand where people said they used the cardboard to even things out, so I tried it. I slipped the cardboard in between the rubber mat and the stand, expecting it to get compressed by the weight as I filled the tank; but I stopped filling when it was about 2/5 full because I noticed the cardboard didn't seem to be compressed at all. Now I'm worried that front edge of the tank is only supported by the rubber that's suspended between the two corners, almost like a hammock, which doesn't seem very stable (especially long-term). My civil engineer brother says that cardboard is surprisingly strong (and granted, I haven't even filled the tank halfway yet), but I would have expected it to cave in more by now--those holes are making me nervous!
I have a few questions--if you can answer any I will be very grateful, and if there's anything I haven't thought to ask please let me know!
1) Based on pictures below and/or my description here, do you think the front edge is sufficiently supported? Can I continue filling up the tank as-is?
2) Has anyone used cardboard to level out their stand with long-term success? (I know cardboard and water don't mix, but I don't have it on the side where I fill the tank.)
3) Would a series of wooden shims between the tank and the tank stand be more reliable? I was thinking of putting in a continuous "wall" of shims that are all touching each other's sides, and pointing in opposite directions so that both edges of the tank's front edge are supported (if that makes sense).
4) Is there another solution that you've used in this situation? Should I just return the stand and hope the replacement is better made, or is there another type of stand that is more reliable?
Thank you for your help!
Gap before adding padding:
Rubber mat padding used:
Wider view of gap before adding padding:
Cardboard and padding added to tank:
Cardboard and padding added to tank, on front left edge where gap is most prominent:
Cardboard and padding added to tank, wider view:
Bonus curious turtle picture- looking forward to that ATBA, periodically dry docking in the meantime: