If you’re a current pool owner who tests and treats the water yourself, you’re probably aware of the basics of testing chlorine and pH levels. You may have also experienced algae blooms (especially in warm, muggy weather) and needed to shock the pool or use an algaecide.
But upon seeing the title of this article, you may be wondering, what are phosphates?
Phosphates feed algae and promote algae growth; they serve as the main ingredient in fertilizer because they are essentially plant food. So when fertilizer (and/or leaves carrying fertilizer) are blown into the pool, phosphate levels will increase. Phosphates can also be introduced to the pool through human contaminants, rain water, runoff, and even hose water used to fill the pool. Testing and controlling phosphate levels helps to prevent algae outbreaks.
“We recommend checking the phosphate level once a week and more frequently if there are unique environmental or seasonal changes in the area; for example, heavy wind, rain, sand or fire storms, as well as during gardening, growing, and plowing seasons,” says Joe Sweazy, Technical Sales and Services Manager for Hach Company/ETS Business Unit, manufacturer of AquaChek®.
AquaChek recently released the new One Minute Phosphate Test, making it easy for pool owners to check phosphate levels. To use, add the powder pillow content to the water sample, shake gently to mix, and compare it to the color chart. The AquaChek One Minute Phosphate Test comes with 20 phosphate powder pillow reagents and a testing vial.
The ideal maximum level for phosphates is 0.1 ppm. If the phosphate level in your pool water is above that level, it is likely to have algae blooms. To treat such algae blooms, you can shock the pool, bringing chlorine level to 10 ppm, and keeping the chlorine at shock level until the algae begins to clear up. Another option is to purchase a phosphate remover and follow the manufacturer’s instructions.
Phosphates are similar to nitrates in that they are both plant nutrients and are used in fertilizer. The difference is, nitrates are much worse to have in your pool because the only way to get rid of them is by partially draining the pool. The good news? Phosphate treatment can help control high nitrate nitrogen levels. Thus, keeping phosphate levels in check is critical to the health of your pool water.