Got my baffles for my 29g sump yesterday. I told them to cut it 11 7/8" x 13. I got them home and they cut them 12 x 13 instead. So it's within 1/8" inch of fitting in my tank. Of course the glass shop is closed on weekends so now I'm faced with one of two ways to go. 1. Try to shave 1/8" off myself with what various handtools I have - dremel; grinder, etc. 2. Wait till Monday and take them back to have them trimmed down by the glass shop. I've never worked with glass before, at least in a manner that I'd have to cut it. It is 1/4" glass, so it's not the thin stuff. I don't want to break the baffles. I was really wanting to build this thing this weekend.