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Where Pool Algae Comes from and What to Do About it

Swimming Pool Algae
By Pools Above Ground
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Where Pool Algae Comes from and What to Do About it

There's nothing quite like having a pool. Be it an above ground pool, inground, cement, or vinyl liner, your pool can provide you and your family with endless hours of summer fun. However, there's a lot more that goes into caring for a pool than most people think. You see, your pool in an environment – a self-contained eco-system that needs very specific things in order to remain healthy. In most cases, keeping your pool healthy means preventing the growth of algae. This slippery, slimy, and downright disgusting natural occurrence is part plant, part fungus, but all bad for your pool water. In the following article, we'll discuss where that pesky algal bloom come from and what you need to do to get rid of it.

Pool Algae: The Basics

Algal blooms, the technical term for what you're experiencing when your pool goes slimy, are a living plant organism. Like other plants, they use photosynthesis to create their own food. This allows them to multiply very quickly and eventually move on to dominate their entire environment. Perhaps the hardest thing about algal blooms is that they are microscopic in size. This means that by the time you start to see clumps of algae taking shape, you likely already have several million inhabiting your pool – maybe more. Of course, the more you have, the more critical it is that you act immediately. The good news is that algal blooms that occur in pool water are typically harmless to swimmers, unlike those that occur in ponds, oceans, and lakes. But even so, an algae outbreak means you won't be throwing any pool parties anytime soon. If you want to get your summer back to normal, you need to act fast!

The Causes of Pool Algae

So, you've identified the problem, now let's talk about the "how" and the "what." These, of course, related to the phrases, "how did it get there?" and "what can I do about it?" The causes of pool algae vary quite a bit, but it usually doesn't take too long to figure out which instance caused your particular problem. Examples include:

Pool Parties

These can overload your chlorine levels with bacteria, chemicals, and dirt, eventually leading to algae formation.

Chemical Imbalance

If something about your pool’s environment is off, it might give algal blooms a chance to take hold.

Undersized Filter or Pump

If your pump and filter aren’t up to the challenge, they may not be keeping your water clean enough to stave off infiltration.

Bad Circulation

Algae thrives in stagnant water, which is a big reason why your pool circulates in the first place. If you’re not filtering at least six to eight hours per day, algae might be inevitable.

Adverse Weather

Hot temperatures and frequent rainfall can introduce nitrogen to your pool. Algae thrive on this gas, which might cause them to take up residence very quickly. Looking at all these factors, you should realize that most pool owners will have an algae outbreak at some point or another – they simply can't always be prevented. So don't feel bad if you find yourself struggling with an algae problem - what really matters is how quickly you handle it.

Treating an Algal Bloom

Below you'll find a series of steps for treating your algae-infested pool. I suggest following each one in order, no matter how bad your algal bloom problem is. In the end, the cleaning and shocking process is the only way to make sure the algae won't return.

Manually Vacuum Your Pool

We all love our convenient little robotic pool vacuums, but they aren't particularly good at dealing with algae. I suggest you get out the manual vacuum and start paying close attention to the areas where algae blooms are forming.

Take a Brush to Your Pool

Algae loves to adhere to the surface of your pool liner where it can avoid being sucked into the pool filter. If you notice any dark or shady areas forming on your pool walls, take out a pool brush and start scrubbing. This will loosen the algae and make it easier to kill.

Rebalance Your Water

A healthy, balanced pool will be a difficult environment for algae to grow. Unfortunately, the presence of algal blooms is often enough to start messing with your chemistry. Get out the test strips and check your alkalinity and pH to make sure you're not "off the grid" on either measurement.

Shock Your Pool

A calcium hypochlorite shock is the standard treatment for an algae problem. You can find shocking treatments at your local pool store. Just remember to shock your pool in the evening or overnight! If to try to do it during the day, the sunlight will inhibit the sanitizing effect by eating up the chlorine before it cleans the pool. As an added tip, put your cleaning tools in the shallow end of the pool so that they get sanitized as well.

Run the Filter

The second half of the shocking process is to continuously run your filter for 8-12 hours. Post shock, your water will be a cloudy blue color with a high chemical content. The only way to get it back to normal is to cycle all the water through the filter. At this point, you may want to add a clarifier product to aid in the process.

Clean the Filter

The last step in the process is to carefully clean your filter so that all the microscopic algae particles don't get circulated back into your pool. I suggest soaking the filter in diluted muriatic acid to be sure, as sometimes algae are remarkably tough to kill. Alternatively, consider replacing your filter altogether.

In Conclusion

An untreated algal bloom will ruin you and your family's summer pretty fast. I suggest you stay ahead of the problem by testing your pool daily. You'll also want to tell your family to keep their eyes out for any cloudiness or other signs that algae might be starting to take hold. Sure, the shock process may take a few days to complete, but it's preferential to taking your daily dip in a pool full of slime.

January 24, 2021