Depends on how the sump & plumbing could be approached. If the glass on the fluval is not tempered & your ok with drilling glass, then you would simply need a couple of bulkheads, plumbing supplies & a 12 pack. If the glass can not be drilled, it will get a bit more complicated in getting the water to drain into the sump & return it back into the main display but it’s doable. All depends on the best & safest approach. If you really want to add a sump, start with finding out if the glass on the fluval is not tempered. If not tempered, look into how glass is drilled.