How to Clean a Green Pool

Is your pool an odd shade of green? Well, you might have an algae problem and whether it’s big or small, you’ll need to take care of it so your pool is safe to swim in once again.

While restoring your pool to proper conditions and eliminating the presence of algae isn’t much of a complex process, it can be a lengthy one. For this reason, you’ll want to be consistent with maintenance to avoid allowing algae to grow and ultimately ending up in a situation like the one we’re going to describe, but we understand that it’s not always possible to clean your pool as thoroughly as possible.

Nevertheless, routine maintenance is a big key in not only eliminating algae in a green pool, but making sure it doesn’t return in the same capacity.

So, below you’ll find the steps you should take to clean a green pool of algae and restoring it to proper swimming conditions.

1. Vacuum Pool to Waste

The first step in getting rid of algae is to set the valve on your filter system to “Waste.” Doing so will prevent any of the algae or debris that is removed from returning to the pool.

So, when you place the filter on the proper setting, you’ll be free to vacuum away!

Be sure to vacuum the entire floor of the pool as even the slightest bit of remaining algae can continue to grow and keep giving your pool water that green look you’re trying to eliminate in the first place.

2. Brush Pool Walls and Floor

Vacuuming isn’t a foolproof way to remove debris and algae on its own. For more intensive cleaning you’ll want to grab an algae brush and thoroughly brush the floor and walls of the pool.

Now, we know what you’re thinking—isn’t it counterproductive to vacuum and then brush the pool?

Actually, it’s not. You see, you want to kill the algae to remove it—and it needs to be in the pool in order to do that. So by brushing the walls, floor, and any other spaces, you’ll remove it from the surface of the pool so it’s floating within the pool which is exactly what you want.

3. Test pH and Alkalinity Levels

After you’ve brushed the walls thoroughly, you’ll need to measure the water chemistry. Since the pool is green, the pH, alkalinity, and chlorine levels won’t be where they need to be.

Specifically, we’re pretty confident that the chlorine level will be low or even nonexistent because if it wasn’t, you wouldn’t be dealing with a green pool.

When you test the chemistry levels, you’ll want to take note of them for reference when you add chemicals later.

4. Add Pool Shock

Pool shock is a chemical that contains a high level of chlorine—enough to kill algae and sanitize the pool water. For optimal effects, we suggest using pool shock that contains at least 70% chlorine. This may seem high, but trust us, this is a much different process than dealing with a pool with chlorine levels that are just a little out-of-whack.

This may be a scary process if you’re not used to adding such a high volume of chemicals, but it’s needed—and may be needed to be completed multiple times if your pool water is a very dark shade of green.

5. Run Filter System

Once you’ve completed the first four steps of this process, it will be time to run the filter system to sanitize and clean the pool.

It’s normal for the rest of the process to take a few days, so don’t turn the filter off until the water is completely clear. Of course, you should keep a regular eye on your pool over the next few days to notice any changes (or lack thereof) to the color of the pool water.

You should notice a gradual progression of the pool water returning to a normal state and once it has that nice, blue tint to it once again, you’ve succeeded!

6. Test and Balance Water Again

When that blue tint to the water has returned, you’ll want to test the water chemistry again (this is where you’ll want to refer to the previous measurements). You should notice great improvements in pH, alkalinity, and chlorine levels—such improvements that they should be back around the recommended levels!

Of course, they may not be exactly where they should, which just means that you’ll have to add more chemicals in small doses. If that’s the case, just keep adding chemicals little by little and testing the water until the levels are where they need to be!

How to Prevent Algae from Returning

As we said, this a pretty lengthy process! Not complex, just time consuming. So, you’re probably wondering how to avoid the need to go through this process again if you’ve already had to complete it. Well, the answer is pretty simple—keep up with routine maintenance.

You should check pH, alkalinity, and chlorine levels at least once per week. However, we recommend doing so at least 2 or 3 times per week. It’s a simple process that can be completed in minutes and by testing the water chemistry frequently, you’ll be likely to catch and irregularities before they get out of hand.

We hope this step-by-step process helps you should you ever be caught in a situation with a green pool and if you’re looking for more help with pool maintenance, check out some of the articles below!