I want to add a fuge to my sump, but the space is limited. I can fit in a box that is 1 foot tall, 1 foot long, and 7 inches wide. Would that be enough space for some cheato on a 180 gallon tank? My nitrates are around 20 to 25 and I would like to get them lower. I might be able to fit in a 15 gallon high if I redo the plumbing to the sump. Would a 15g high tank be drillable on the side up near the top?