By Natural Chemistry



Model # 05236

Alternate Part #'s NC05236EACH, NCH15236NCM

Product Description

Natural Chemistry PHOSfree Extra Strength 3 Liter - Extreme Phosphate Reduction

PhosFree Extra Strength is a highly concentrated formula that quickly reduces very high phosphate levels. It is the only patented formula that removes phosphates from the filter. All 5 and 55 gallon containers are specifically designed for use with Natural Chemistry's Automatic Dosage Dispenser


  • Compatible with all sanitizers and pool surfaces
  • Non-toxic and will not harm the environment
  • Reduces pool and filter maintenance


  • 100ppb-1000ppb: 25oz (740mL) per 20,000 gallons (75,000L)
  • 1000ppb & higher: 50oz (1.5L) per 20,000 gallons (75,000L)

How to Apply:

  1. If pool has algae, follow dealer instructions to treat
  2. Clean or backwash filter
  3. For phosphate levels over 100ppb and under 1000ppb add 25 oz (740mL) per 20,000 gallons (75,000L)
  4. For phosphate levels over 1000ppb add 50 oz (1.5L) per 20,000 gallons (75,000L)
  5. Shake bottle well and with filter pump running add dose directly to skimmer
  6. Clouding of pool water may occur when adding this product. After 24-48 hours, vacuum pool surface to filter


  • It is important to retest pool water following completion of each phosphate removal treatment.
  • Repeat if necessary until phosphate level is below 100ppb
  • Maintain phosphates once they are under 100ppb with a weekly maintenance of Pool Perfect+PHOSfree

Features & Benefits:

  • PHOSfree is formulated from lanthanum (rare earth compounds)
  • Specifically designed for high levels of phosphates
  • Highly concentrated

For our complete line of Natural Chemistry Pool & Spa Chemicals

Product Specifications

3 L
Pool Type:

?     Asked on 10/18/2012by Guest

I've been told that my pool water is high in phosphates. I have used a phosphate remover to lower the levels but they were high again shortly thereafter. Am I doing something wrong?

A  Answered on 10/18/2012 by InyoPools Product Specialist Patrick P.

There are several reasons why the phosphates can increase. Certain pool chemicals contain phosphates. Fertilizers and pollen can add phosphates into your pool too. You may need to drop down the phosphates as low as you can and use a phosphate remover on a weekly basis for maintenance.

?     Asked on 10/26/2012by Guest

Do you sell a test for phosphates?

A  Answered on 10/26/2012 by InyoPools Product Specialist Patrick P.

Yes we do. You can find it here.

?     Asked on 11/27/2012by Guest

Will using Phosfree raise my filter pressure?

A  Answered on 11/27/2012 by InyoPools Product Specialist Patrick P.

Phosfree raises the filter pressure because it puts a coating on the filter media (sand, d.e., or cartridge) so it is able to catch the phosphates. After an 8-10 psi increase in the filter pressure, the filter should be cleaned or backwashed.

?     Asked on 7/12/2016by Joe

How does one vacuum the pool surface as directed by the product instructions?

A  Answered on 7/16/2016 by InyoPools Product Specialist Lennox H.

Hi Joe, You can use a Vac Head or Automatic pool to vacuum your pool surface after using this product.

?     Asked on 8/9/2020by Inyo Visitor

When would this be delivered?

A  Answered on 10/29/2020 by InyoPools Product Specialist Hector F.

Hi Barbie, this item is in stock and has an approximate delivery lead time of 3-7 business days. 


Est. Repair Time

More than 8 hrs

Tools Needed


Phophates higher than 1000

Written on 5/27/2020 by Guest

My phosphates kept measuring very high, above 1000 on multiple tests. I decide to tackle it with the Phosfree Extra Strength. Per the instructions on the bottle, I did the following steps.

1. Vacuumed the entire pool to make sure to get all dirty I could out of pool.
2. I thoroughly cleaned the filters.
3. I poured in the phosfree and ran the filters for 48 hours continuous.
4. I vacuumed the pool again.
5. I cleaned the filters again.

My next test showed that my phosphates had decreased to less than 100!

Were these instructions helpful? 


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