I'm doing a water test on my new Aqueon Proflex 4 sump on a new stand. This is the first time I've ever dealt with anything acrylic and I wanted to find out how seriously I should be taking gaps underneath the sump. I'm using thin (about 1/16") urethane foam underneath the sump. Here are the pictures of the gaps:
As far as I can tell it's actually the sump that's not perfectly flat not the stand (the sump wasn't square either). Here are pictures of the same spots with straight edges:
Is this a concern I should fix? I've read acrylic expands when in contact with water, so could this gap fix itself maybe? Looking for suggestions on how to proceed (keeping in mind that I want to keep the risk of a leak to a minimum).