Spotting on glassware is usually mineral residue left behind as droplets evaporate, not a sign the detergent is failing. Rinse aid works by letting water sheet off rather than bead, so there is nothing left to dry into a mark. Hard water areas need more of it, and hospitality venues serving glassware notice the difference first. Check whether your tablets already include it. See tablets, glassware and kitchen cleaning.

Dishwasher rinse aid bottle on a bright kitchen bench with clean glassware, plates and an open dishwasher.
Rinse Aids for Dishwashers

Shop rinse aids for dishwashers, glassware, cutlery, crockery, office kitchens and hospitality venues.