Controlling phosphate levels in you spa is a piece of cake with Natural Chemistry Spa Phosfree. Formulated with lanthanum (rare earth) compounds, this product coats the filter media and traps nasty phophates. If there was a spa on the moon, NASA would use Spa Phosfree because of it's "space-age" characteristics!
Directions:
Drain or Re-fill or New Start-Up: Add 16oz. (4 large capfuls) per 400 gallons directly to spa water with filter operating. Temporary turbidity may be experienced with new spa start-up.
Weekly Maintenance: Add 1oz. per 100 gallons weekly