Spas can sometimes experience problems that sanitisers and oxidisers cannot deal with, such as: foaming, cloudy water that does not respond to shock dosing, staining and scaling. Anti-foam, clarifiers and stain & scale control chemicals are available to address these issues.
Boric acid is a very useful water enhancing additive as it helps to stabilise pH and increases the efficiency of other chemicals. It also gives the water a nice silky feel and prevents tangling of long hair. Bioguard Spa Velvet is 100% boric acid, and has the added benefit of giving a pleasant rose fragrance to the water.