They have that spot for 3" Chlorine Tabs. He (previous owner) said just to keep 4 or 5 in it and then shock it from time to time, plus check the PH. Other than that, its just cleaning once a week. Bout all we do with the Hot tub. We have a floating basket with Bromine tabs, then shock it and some clearafier when it gets cloudy. We have to get someone to move it and set it up for us sometime soon but I got to pick out the spot and build something to put it on plus get the 220 ran to it
proud member of "Team Cup"