take the two ten gallons

take a glass cutter

take one ten gallon, on the short side, use the galss cutter to cut that side off

do the same for the other ten gallon

take either caulk or 100% sillicon, i heard sillicon is better, but caulk works too

and then put either the caulk or sullicon, on the edge of the tank you cut, then place them together, and if the stuff kinda oozes everywhere, making like bubble type things, i guess you could wipe it so it is cleaner

then wait at least 48 hours, or else the fumes will annoy your snake

and as for the sterdiness of it, it might be a lil weak, so i wold suggest placing some sort of board under it