I used silicon to stick in an acrylic baffle. The baffle was too thin (very thin and it bowed and leaked into the section it was supposed to divide because the bowing pulled it from the sides) HOWEVER, the silicon actually did hold it very well because the silicon was not going anywhere and the acrylic was sandwiched between them. Had I not been cheap and used scrap 1/8" acrylic and used 1/4" instead, I would be using that as a baffle now, instead of having a plastic storage box as a skimmer/drain section.