We're on Instagram!

Follow @thepoolandspahouse on Instagram and live your best #poollife with us!

Follow Us

We're on Facebook!

Follow The Pool & Spa House on Facebook and live your best #poollife with us!

Follow Us


See what our customers are saying!



Streamline your ordering process with our Pro Site!



We're growing! Our brand new store will be opening in West Linn, SOON! Stay Tuned!


Mailing List

Be the first to know about discounts, promotions, your personal water analysis results, water care tips and reminders!




Spa Sentry is a phosphate buffer that maintains a stable, comfortable pH in spas. Spa Sentry softens the water by removing calcium. Its built-in corrosion inhibitors protect the equipment so you can enjoy the easy maintenance of softened water. Do not use in plaster or tile surface spas.

  • Maintains stable, comfortable pH
  • Softens spa water
  • Protects equipment
  • Simplifies water balance
Product Info

Available sizes: 1 quart

  • Phosphate buffer
  • Corrosion inhibitors
  • Water clarifier
  • Not for use in plaster or tile-surface spas
How To Use

IMPORTANT: Leave heater OFF during the Spa Sentry procedure. You may turn the heater on when the water has cleared.

  1. Drain and clean the spa surface with SpaGuard Surface Cleaner.
  2. Clean filter with SpaGuard Filter Cleaner and Degreaser.
  3. Refill with fresh water.
  4. If Total Alkalinity is greater than 150 ppm and pH is higher than 7.6, use pH Decreaser to lower pH to 7.4.
  5. If fill water has calcium hardness less than 150 ppm, add 1 qt. of Spa Sentry per 300-500 gallons. Clean the filter after 24 hours. If the calcium hardness is greater than 150 ppm, add 2 qts. of Spa Sentry per 300-500 gallons.
  6. Add the first quart, wait 24 hours, clean filter, add the second quart. The water will become cloudy upon addition. This is calcium precipitation.
  7. As the filter removes the calcium, rinse frequently. When the water is clear, you may turn on the heater.

Product Notes:

  • The pH should remain stable for up to 60 days. If the spa has not been drained after 60 days add an additional quart of Spa Sentry.
  • If Spa Sentry is used in a system with Brominating Tablets, the life of Spa Sentry is severely reduced. Brominating or Chlorinating Concentrate are recommended.
Drop Click