HT Protection Plus is a combination of HT Stain & Scale and a Traditional Clarifier.
If your water has a high mineral content, it’s best to use full strength Stain & Scale to protect your spas and HT Natural & Clear to keep your water crystal clear.
If your mineral content is low and your water stays pretty clear, then just adding a few ounces of HT Protection Plus is fine.
But whenever using a Clarifier, it’s good idea to use Sun Sorbs to help prevent getting a scum line along your acrylic shell.
Sun Sorbs simply float on the water capturing oils, they seem silly, but they really work.