Monday, October 8, 2018

What are these White Flakes in my Swimming Pool?


Chances are if you have a salt water pool you have seen some type of white flake blowback at one point or another into your pool or spa. The amount of these white flakes varies but, in many cases, your entire pool surface can be covered in them. I’ve had pools where I fill a whole leaf rake with them and some with Polaris Pressure cleaners where the bag is bursting with white flakes.




There are three possibilities of what the white flakes are.  The first one and least common is what is known as White Mold. It is not very common and to cure your pool of this you would need to bring your chlorine level up to very high levels, around 10-20 ppm. But in most cases the white flakes are not White Mold and something else.

The next possibility is that these flakes are coming from your salt cell plates and that they are small particles of calcium flakes that come back through the return lines. Usually these flakes are pretty thick and look like the calcium that forms on your pool tile. This does happen, and I have seen calcium flakes in some pools. But this is not as common as the third and final possibility.

This will sound strange and really out of the realm of possibility but those white skin like flakes in a salt water pool are most likely a reaction of the salt system with Phosphates in your pool. Even very low levels of Phosphates can cause this, and I have seen these white flakes with both very high and very low Phosphate levels. It doesn’t really take much Phosphates in the water to cause this reaction.

I find that the Pentair cells are the main producers of these white flakes. The Hayward cells to a lesser degree. I was told about this cause by a very experienced Pentair Warranty Service Technician. I didn’t really believe him, but he suggested that I should add some Phosphate remover to my salt water pools that have the white flake blowback. So, with no real reason not to give it a shot, I started using some PHOSFree in the pools with the white flake blowback.

Wouldn’t you know it, the white flakes started to go away in the pools that I was treating with the PHOSfree. In some cases, they disappeared entirely, in other cases there was an 80-90% reduction. It was pretty amazing.

I typically use 2 capfuls or 8 oz. each week and add it directly to the pool skimmer as the pool is running. After about one month of this treatment the white flakes are pretty much gone. If they come back I resume the treatment again. You can also just add the maintenance dose each week to prevent the whiter flakes from returning. The treatment is very easy to do any very effective.

If you are dealing with a pool with this white flake blowback from a salt water system, try adding the PHOSfree each week. The results will surprise you.