I am water testing my new Red Sea 3xxl 900. When I filled up the sump which sits on a foam pad in the stand it looks as though there is water or air trapped under there, or just that the foam is being pressed against the glass more in a specific spot. I did notice this right away, however monitor over 24 hours it does not appear to have spread at all. There is no water coming out of the stand and all the foam that I can feel under the sump is dry. Does this look like a leak or is it normal for glass to look like this when sitting on some sort of pad.