Using PhosFree for algae control

[PoolDoc]

1. Maintaining very low phosphate levels (< 0.125 ppm) DOES inhibit algae. But, it doesn't kill algae.

2. Many, maybe most, pools have NO trouble with algae if effective chlorine levels are maintained -- chlorine levels that are 10% of the CYA level or higher will do it.

3. A few pools have problems with recurrent mustard algae, in spite of adequate chlorine levels. I don't know why this happens.

4. It's more difficult to maintain low phosphates than most realize. Many of the tests are very inaccurate; city water may have 2 - 3 ppm (2,000 - 3,000 ppb) of phosphates; many commonly sold pool chemicals CONTAIN phosphates, or turn into phosphates.

5. It's completely useless to use 'some' phosphate remover: until phosphate levels go below 500 ppb (0.5 ppm) there's no effect. To be fully effective, you need to go below 125 ppb (0.125 ppm).

6. Phosphate removers vary greatly in quality. By far the best choice is Orenda's PR10000 removing 10,000 ppb (10 ppm) from 10,000 gallons of water. I've recommended other products in the past, only to discover they were playing games with the concentration!

Orenda PR10000 Phosphate Remover @ Amazon

7. After testing numerous phosphate kits and strips, only the AquaChek and Taylor tests seem to be accurate enough to be useful, and the AquaChek is only helpful once you've greatly reduced the phosphate levels. Both kits are a bit of a pain to use.

Hach (AquaChek) Company 562227 Phosphate Test Kit @ Amazon
Taylor K1106 Phosphate test @ Amazon

8. Using phosphate removers *may* be worth trying *if* (a) you have recurrent algae in spite of reasonable chlorine levels OR (b) you are frequently away from the pool for more than 3 days, but ONLY if you are able to (a) test accurately, (b) dose adequately, & (c) avoid using of phosphate sources.

9. Some phosphate removers may cloud the water temporarily; all can cause the filter to clog somewhat. As a result, if you have typical levels of phosphates in your pool, it may take a week or more to lower phosphates sufficiently to be effective.