Some tanks cannot be drilled from the bottom. I would check from the manufacturer to be sure before you drill. Tempered glass will not drill. At least not with the results you are looking for
*180 gal Display, 100 gal basement sump, 33 gal refugium, 3x250 MH, 2x160 VHO actinics, zoos, some softies, LPS & lots of acros and other SPS.
*100 gal prop tank plumbed into main system w/ 2x96 PC lights and 1x150 MH,