How to Get Rid of Pink Slime in Your Pool—And Keep It Gone

Every experienced pool owner knows that sometimes uninvited guests show up to the pool party. But if you’ve noticed pink streaks at your waterline or in the crevices of your pool, or what looks like pinkish algae floating on the water’s surface—it’s time to kick this particular guest out.

Here’s why: If pink slime crops up in your pool, it’s a sure sign that something about your chemical balance is off. And it’s actually not just an indicator of an unsafe chemical environment—it’s also toxic itself. 

Though pink slime happens to the best of us, it’s absolutely preventable. I’ll explain how to get it out of your pool—whether you sanitize with chlorine or biguanide—and how to make sure it never, ever comes back. You’ll be swimming in safe waters again after just eight steps. 

But first, let’s break down what that slime really is.

What is that Pink Slime Anyway?

You might assume that since pink slime has grown in your pool and sort of looks like algae, that it’s pink algae. It’s not. In fact, some pool companies even market for this misunderstanding with products intended for “pink algae.” Seriously, pink algae doesn’t exist.

Chances are you’ve seen light pink streaks in your shower before—especially under a leaky bottle of shampoo or soap. That’s pink slime, and it feeds on the mineral and fatty deposits of bathroom products.

Pink slime formally goes by Serratia Marcescens, and it’s actually an airbourne bacteria that loves moist, warm environments. No surprise, then, that it can sometimes crop up in the swimming pool.

Why Does My Pool Have Pink Slime?

Maybe it’s cropped up on the corners, crevices, pipe-fittings, or light fixtures of your pool. Or maybe it’s situated at your pool’s water line. The point is that you’ve got pink slime, and you want to know why.

Well, the news isn’t great: pink slime means that you either have water that isn’t properly balanced, or your pool itself isn’t clean.

On the flip side, once you maintain a clean, balanced pool, you won’t have to worry about this bacteria ever again.

Everything that happens in your pool relies on your pump. Keep pink slime gone with the ultra-powerful BLACK + DECKER 3 HP Variable-Speed Pump. It includes a warranty, qualifies for utility rebates, and pays itself off in up to 80% energy costs saved in all stages of operation.

Pink Slime is Gross. But Is it Harmful?

Pink slime is a bad time—for your pool and your health. It doesn’t just look gross, it’s actually harmful. Serratia Marcescens can enter the body through the mucus membrane, such as the eyes and nose, or through an open wound. Once it enters your system, it can cause a spectrum of illnesses, such as urinary and respiratory infections, endocarditis, wound infections, eye infections, meningitis, and more.

If you do see pink slime in your pool, it’s best to call off swimming until you can eradicate it in this next section. And once it is gone, you’ll want to keep it gone. This is about keeping you and your fellow swimmers safe.

Got a Chlorine Pool? Let’s Get that Pink Slime Outta There

Ready to make some moves and get your pool back to safe for swimmers? I don’t blame you. All you’ll need is your regular pool chemicals, a 360-degree pool brush, and an “algaecide” for “pink algae.” (Again, pink algae doesn’t really exist.)

  1. Purge Out the Slime from Your Pool Filter

In order to understand why this step is so important to start out with, let’s quickly revisit just how your pool filter operates. While sanitizer neutralizes microscopic bacteria, it doesn’t actually physically remove them. Water circulates through your pool filter so that it can catch the bigger, badder gunk, and keep it out of your water. And you bet pink slime falls under that category.

The downside to the pool filter is that if your pool has pink slime, it’s almost guaranteed that your filter does, too. If you have a sand or D.E. filter, backwash it now. If you have a cartridge filter, clean out or replace the filter media. 

This step will prevent the filter from reinfecting your pool with pink slime. Because that’s one vicious (and nasty) cycle nobody wants.

2.              Balance that Wonky Water 

If you’ve got pink slime in your pool, your chemical balance is off. It’s an exponentially worsening situation: chemical imbalance is what allowed the pink slime to occur in the first place, sure. But pink slime also quickly exhausts your sanitizer and other chemicals, throwing the entire balance of your pool way off. This is one hungry bacteria we’re dealing with. 

Now is the time to really make sure your chemical balance is back in check. The most important chemical to balance, and the most thrown off by slime other than sanitizer, is your pool’s pH. Make sure it’s back between 7.4 and 7.6. The sweetest spot to go for is 7.5. 

3.              Turn Off the Pump 

Power that pump down. We’re going to need still waters for these next steps to really take hold. This process is about to get real—and involve a fair amount of elbow grease. Everything you do from here on out is really going to count. 

4.              Brush Out the Pool 

Here’s your chance to skip the gym. Welcome to arm day.  

Using the patented 360-degree pool brush, thoroughly brush down the pool’s bottoms and walls. I recommend this brush because it’s able to get all those tough-to-reach crevices, such as on pool stairs, behind ladders, around jets, and in any other corners. That’s likely where the pink slime will be the most concentrated. 

Use the BLACK + DECKER 360-Degree Bristles Pool Brush to kick slime from your pool walls and floors—more quickly, and more thoroughly. It was developed by longtime pool maintenance experts to prevent aches and pains associated with getting hard-to-reach corners.

5.              Add the Chemicals and Take a Break

Those products I mentioned that advertise that they’ll kill pink algae, even though pink algae isn’t a thing? Yeah, you’re actually going to want to use one of those now. They’re not labeled accurately, but they are effective—and we’re going to want all the help we can get here.

Next, it’s time to shock your pool. And I mean really shock your pool. I’m talking tripling or even quadrupling the amount of shock you usually add to your pool—and since you usually want to add one pound of shock for every 10,000 gallons of water, that’ll be three or four pounds of shock for every 10,000 gallons. 

Remember, you always want to shock your pool at dusk or night—otherwise, the sun will burn it off before it can do its job. And you really need it to work this time. Once you add the shock to your pool, test the water to make sure your chlorine level is at around 5 parts per million (ppm). Then, let that shock sit in your pool overnight. Keep the pump off!

6.              Vacuum the Pool 

Promise, this part won’t suck too much. I do have some bad news for you, though: an automatic cleaner is not going to work for this step. If you’ve already made the time-and-arm-saving decision to get a robotic cleaner, it’s time to dust off that manual vacuum. Hopefully, it’s been a while since you had to do this—and hopefully it’s a long time before you need it again.

While manually vacuuming your pool, be sure to vacuum to waste. You do not want what you’re vacuuming out to reenter your pool! And if you drop too far below the water line, use a garden hose with a metal filter to refill. 

7.              Clean the Filter Again 

Take two. You already cleaned the filter out once, and now it’s time to do it again for extra measure. This time, use a chemical cleaner made for your specific filter type. You’re almost there—a safe swim is just around the corner of this next step.

8.              Run the Pump and Keep It Balanced

Finally, it’s time to fire up the pump again. But unfortunately, you’re not quite done yet. It’s going to take about a week to really be sure that pink slime is gone, through brushing and vacuuming your pool every other day and frequently checking your water levels. Your chlorine levels for this time should remain at 5 ppm. 

After a week of this, let your chlorine level drop back down to normal and rebalance your water. Finally, slime be gone. Your pool is back to being safe!

Was an unclean pool the reason you got slimed? It’s time to give your automatic cleaner a much-needed upgrade by switching to the Blue Torrent MyBot Inground Robotic Cleaner, which works powerfully on its own to keep your walls and floor sparkling clean. As customer David Lain says, “Very pleased. My wife loves it. 

Biguanide Pool? Make Some Adjustments

If you use biguanide to sanitize your pool, you’re going to have to make a few minor adjustments to the steps above to wipe out that pink slime.  

Get the Right Chemicals

Different sanitizer, different chemicals. Instead of a “pink algae algaecide” you’ll want to add a biguanide algaecide instead. This applies to algaecide in general—the normal stuff just isn’t good to biguanide pools.

You’ll also want to add an oxidizer instead of pool shock. You’ll still want to triple or quadruple your usual dose to really make sure that pink slime is in for a reckoning.  

Increase Sanitizer 

While the usual range for biguanide is 30 to 50 ppm, add enough to raise it to 50 ppm. You’ll want all the biguanide your pool can take for this problem.  

Keep it Balanced—For Shorter

No need to keep your biguanide levels at 50 ppm for an entire week. Instead, check your levels before cleaning the pool filter the second time. If your biguanide has dropped below 50 ppm, bring it back up, clean the filter, and run the pump. Once your water clears, you’re in the clear, too.

Now that you’re back to using your pool safely, are you looking to extend the swim season as much as you can? A heat pump is the answer for you—but you’ll want a powerful unit that will save you on your energy bill every month, like the Energy-Saving ComforTemp Pool Heat Pump 95,000 BTU to heat 18,000 Gallons. According to customer Steve, “Simple install and simple set up. Heated my pool from 66 to 82 degrees in about 2 complete days.”  

Prevention is Better Than a Cure!

Thankfully, preventing pink slime is fairly easy—much easier than eradicating it from your pool. All you have to do is be diligent about keeping your pool clean by brushing it three times a week and vacuuming it once a week (or allowing your automatic cleaner to do the vacuuming work). You also need to maintain the chemical balance of your water once a week and shock your pool once a week—or, if you have a biguanide pool, use an oxidizer.  

This is all fairly basic stuff, but since you recently got slimed, it might be a good idea to read up on the easiest pool maintenance routine. Next time, no slime!

Want to get rid of the mustard algae in your pool? Learn more here. And if you want to get rid of white water mold, here is the solution.

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