I just picked up the baffles for my sump from the glass store today. They are a snug fit. They slide into place but there is very little wiggle room (one of them wedges perfectly in with no space between it and the tank wall). Is this a problem? I read somewhere else that sometimes tight fit baffles expand and have resulted in cracked sumps? Is this only for acrylic baffles since they expand more than glass or is this a risk for my glass baffles as well? I really want to build the sump tonight but I don't want a burst sump in a few months - should I take them back to the glass shop and get them to shave an 1/8 of an inch off?