How to Get Rid of White Water Mold and Pink Slime in a Pool

by Matt Giovanisci | Last Updated: July 28, 2013

Pink slime and white water mold seem to go hand in hand. They are commonly misunderstood in the swimming pool world, but we are going to clear some things up.

Here are the facts about pink slime and white water mold:

When toilets, showers, sinks, and bathtubs get that orange color stain, that’s pink slime – not metals. Pink slime and white water mold can grow wherever there is water.

[NOTE: Since they are very resistant to pool chemicals, including chlorine, we are going to be using some mega doses to get rid of it, so be prepared.]

Now that you’ve identified the problem and learned the facts, let’s get rid of it.


Getting Rid of Pink Slime and White Water Mold

1. Clean!

Manually clean and remove all the pink slime and white water mold you see. Check inside the filter system, in and around the skimmer and return jets, behind ladders, and in very shady spots of your swimming pool.

2. Shock!

Before you add any chemicals to your pool, make sure to pH (7.4 – 7.6) and alkalinity(100 – 150 ppm) are at the right levels.

I recommend quadruple shocking your pool with chlorine shock. That means adding 4 pounds of calcium hypochlorite shock per 10,000 gallons of water. Yes, this is a lot, but like I said, these elements are very resistant to pool chemicals, including chlorine.

3. Filter!

Run your filter continuously for 24 hours. Afterwards, it would be a good idea to chemically clean your filter system using a filter cleaning chemical.

4. Test!

After about 4 days or so running your filter system and continuing to clean your pool using a brush and manually vacuum, it’s time to test your water.

Use a test kit, test strips, or bring a sample of your water to your local pool dealer to get it tested. Make sure you bring your pH and alkalinity back up to the right levels.

How to Prevent Pink Slime and White Water Mold

We know that they are naturally occurring problems, so we have to defend our pool against it.

Just like using a bleach in your toilet to prevent pink slime, we are going to do the same with a pool, but instead, we use chlorine.

Make sure you keep the proper level of chlorine in your pool at all times: 3ppm (parts per million). And brush and vacuum your entire pool often – I recommend doing this twice a week.

Happy Swimming!

Matt Giovanisci, the founder of Swim University®, started in the pool and spa industry at age 13 and moved to bigger companies along the way, helping thousands of pool and hot tub owners every year. He wanted to share his knowledge and unique teaching style on a larger scale, so he launched Swim University® in 2007. Since then, he's worked to make pool and hot tub care easy for over 10 million homeowners. And each year, he continues to help more people with water chemistry, cleaning, and troubleshooting.

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