Concerning the split water tank. We did the same to an Ionics tank by filling it up to quick. The air couldn't escape quick enough and it split the top of the tank open.
We repaired ours with black Sikaflex silicone sealant. It hasn't leaked since.
Lightly sand the outside edge of the split with sandpaper. Clean with a degreaser. Run two lengths of 2" masking tape along the original weld lines. Pry open the tank with a plastic wedge and dry the joint as much as possible. Using a decent silicone gun, apply silicone in the joint. Remove wedge so the joint closes then find something to hold the split joint together. Now run a thick bead of silicone to the outside of the joint and smooth it out evenly with a wet spreader. Try and keep the silicone as a thick smooth bead. Remove the two strips of masking tape when the silicone is still wet. Wait to cure for two days before use.