How To Remove White Water Mold In Your Pool (Step-by-Step)



Let’s talk about white water mold in your pool.

Yes, it’s unpleasant and unsightly, but it’s also important to be aware that if your swimming pool isn’t well-maintained, mold can easily form infecting the pipes, filters, and pool water.

This article will tackle what it is, how to get rid of it, and more importantly, how to prevent it from forming in the first place.

What Is White Water Mold?

White water mold is not the result of a lack of chemicals, or too many chemicals in the water, but rather, it’s a naturally occurring fungus that’s already present in water. It will look like shredded tissue paper floating around in the water.

Usually accompanying white water mold is its equally delightful friend, pink slime — often referred to as pink algae, even though it’s not technically algae.

Pink slime is a bacteria that grows on top of white water mold. The mold is essentially an overgrowth of biofilm, which is a bacterial film that’s found on pool surfaces.

You’ve probably encountered this stuff in your bathroom. If you go a few weeks without cleaning your shower, you’ll quickly see some pink slime building up in the corners as well as on your shower curtain.

In pools, white mold is usually found in hard-to-reach places where there’s poor circulation – areas like pool lights, ladders, in the skimmer, skimmer baskets, and behind the return jets. As it likes plastic, it can even grow on your pool toys, so be sure to check and clean them regularly.

In most cases, if you have white water mold floating in your pool, it’s been injected through the return jets, which means it’s probably present in your entire piping and filtration system. Gross!

What Causes White Water Mold In A Pool?

A common misconception is that white water mold happens as a result of pool water that isn’t properly balanced. The presence of biguanide being a contributing factor is another misconception that holds no merit. 

In reality, white water mold (and pink slime) is just a natural side effect of water that comes from your garden hose or tap. 

As mentioned, this type of mold loves plastic surfaces, so when you’re filling a pool with a hose, it’s a good idea to let it run for a couple of minutes so any potential mold inside the hose doesn’t get transferred into your pool.

Why Is Pool Water Mold A Problem?

White water mold is actually not harmful, but the pink slime bacteria is. 

In any case, it’s a nasty thing to deal with. This is because it most likely won’t just be floating in your pool water, but will be in your pipes and filters as well. That means you’ll have to do some big-time cleaning of your pool to totally eradicate it.

Also, where there’s mold, bacteria will eventually follow. The pink slime that forms on top of white water mold is dangerous to humans, causing respiratory tract issues, pneumonia, and urinary tract infections. It can enter your body through your eyes, nose, or if you have an open wound. Pink slime is definitely something you won’t want in your pool (or home for that matter).

Halogen-based sanitizers like chlorine and bromine also have a hard time fighting against white water mold. But fear not, there is a way to get rid of it.

How Do You Fix White Water Mold In Your Pool?

White water mold is very stubborn. To get it out of your swimming pool you’ll have to follow a strict cleaning regimen, and even repeat parts of it to ensure the mold is completely taken care of.

Step 1. Clean Out Your Filter

When you have white water mold issues, chances are high that the mold is already in your pipes and filtration system. Cleaning your filter needs to be the first step because it can’t be effective if it’s already clogged up.

So take a hose to your cartridge filter and give it a thorough rinsing, or backwash your sand or DE filter

Step 2. Balance The pH Level

The pool’s pH level will need to be balanced so we can execute Step 3 safely. A pool’s pH level should be in the 7.2 to 7.6 range, with 7.4 being the ideal number. 

You can use test strips or a liquid test kit to keep your water in check.

Step 3. Shock Hard!

This step requires you to shock the pool with chlorine in order to kill the mold. 

Now, I know what you are thinking. Didn’t I just say sanitizers like chlorine have a hard time fighting white water mold? Yes, I did. 

However, they’re still effective. You just need to use a TON of it.

When it comes to shocking, the rule is 1 lb. (usually 1 bag) of shock per 10,000 gallons of pool water.

For white water mold, you’ll have to triple or quadruple the amount of shock used – 3 or 4 lbs. of shock per 10,000 gallons.

Step 4. Brush, Pump & Brush Again

Using the right brush for your surface (finish) matters. Use soft bristles for vinyl/tile finishes and steel bristles for plaster/concrete.

Brush thoroughly, and make sure you get into the spots mold likes to live in – around ladders, the pool skimmer, the return jets, and any other “dead spots”.

Then, run the pump for an entire day. This will give the filter time to catch as much of the mold as possible. 

Then, brush it all over again. If you think you got all the mold out on the first go around, you haven’t encountered mold before.

Step 5. Vacuum

Step 5 requires the big guns – manually vacuuming out the mold from your pool. Once you’re finished, you may notice the water needs to be topped up.

You can do so with a garden hose, but make sure you run it for a few minutes before adding water to the pool. You never know if mold is growing inside the hose!

Step 6. Clean The Filter & Retest

Lastly, clean out the filter again, retest, and rebalance the water.

At this point, we would recommend using a chemical soak for your cartridge, or filter cleaner for your sand/DE filter.

How To Prevent Mold In Your Pool

The best thing you can do to prevent mold from entering your swimming pool is simply to keep it clean. This means following a regular maintenance schedule. 

Run the filtration system regularly, brush regularly, and clean off the surfaces that sanitizers have a hard time with. And of course, keep your pool water balanced at all times, and use the proper amount of sanitizer.

It’s A Simple Fix!

While it can be shocking to see your beautiful pool in such bad shape, know that it can be brought back from this state.

By following the steps outlined above, you can get rid of white water mold in the pool, and by practicing basic maintenance procedures, you’ll greatly reduce the chance of ever developing this type of pool problem.

Categories: Pool Care, Pool Maintenance