Natural Chemistry

Natural Chemistry Stain Free 1.75lb.

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Stainfree​ is a citric acid product that removes metal staining on pool liners and finishes. Stainfree​ is ideal for treating staining on all pool surfaces and is compatible with all sanitizing systems. Use Natural Chemistry's Metalfree​ and you have the ultimate 1-2 combination for stain fighting!


1. ​ Balance pool water chemistry before using Stainfree: pH:7.2-7.6, Alkalinity: 80-120ppm, Calcium Hardness: 200-400ppm, CYA below 50ppm, Phosphates: below 100ppb Note: Stain removal products work best when the pH is on the lower side of acceptable range (7.2)

2. ​ Important:​ Before starting the metal stain removal or water discoloration process (step 4), a pulp-based filter aid​ must be added to cartridge and sand filters. DE filters must be properly charged.

3. ​ Lower chlorine level to 1ppm or less (A high chlorine level or adding oxidizing agents during the process will prevent Stainfree​ from working as designed.)

4. ​ ● ​ Surface Staining: If the surface is stained, add 1lb of Stainfree​ per 10,000 gallons as close to the stained area(s) as possible with the pump off overnight.

​ ​ ​ ​ ​ ​ ● ​ Water Discoloration: If the entire body of water is discolored, put the pool on recirculate, add 1lb of Stainfree​ per 10,000 gallons to the pool water evenly around the edge. Let the circulation run for one hour. After one hour, shut the pump off and let sit overnight.

5. ​ Before turning the pump back on, brush the pool walls and floor thoroughly.

6. ​ Turn the pump back on and add Metalfree evenly to the pool around the edge at a rate of 33.9oz per 20,000 gallons.

7. ​ With the pump still on, vacuum the pool walls and floor thoroughly.

8. ​ After vacuuming, clean filters:

  • Sand filter- backwash for at least 3 minutes and then rinse for 2 minutes
  • Cartridge filter- clean filter and filter tank thoroughly
  • DE filter- backwash and recharge with DE

9. ​ Test and rebalance water. DO NOT SHOCK THE POOL FOR AT LEAST 1 WEEK.

  • Note:​ ​ If chlorine level is low, add small amounts of chlorine. Do not exceed 2ppm. For salt generator pools, a granular shock is recommended instead of turning the generator to its boost (super chlorinate) function after the recommended 1 week.

10. ​ Use Metalfree as a weekly maintenance to prevent future metal staining. Apply 4oz per 10,000 gallons once a week.