Elegoo Mercury Plus 3.0 wash / cure station - wimpy motor can't handle underwater curing

I'm new to resin printing, still learning a bunch. I'm using an Elegoo Saturn 4 Ultra 16k printer and also got the Elegoo Mercury Plus v3.0 wash/cure station to go with it. I have done a couple successful prints so far but curing them, even for 15-18 minutes, seems to leave a rubbery, slightly gummy surface. I have seen that curing underwater or at least without the presence of oxygen can help solve this.

I tried filling up a small container of water and placing it on the rotating curing tray of my station, but it seems as though the motor doesn't have enough torque to spin the tray with a heavy glass container of water on it. It sort of stalls out while making sad motor noises.

Any tips or input would be appreciated!