Aquacheck Borate Test Strips - 25 strips per bottle. Sodium tetraborate pentahydrate is used as a pool additive under such names as Proteam's Supreme, Bioguard's Optimizer Plus, Poollife Endure, Guardex Maximizer. What are the benifits of borate in the water? More stable pH, Algaestatic properties, reduced chlorine usage, silkier feeling water--less skin and eye irritation, clearer, 'sparkling' water.