Last Updated: January 16th, 2019
A greenish swimming pool crashes your pool party before it even begins. Algae are one of the most disgusting, aggravating things about owning a swimming pool. Why would anyone choose a greenish swimming pool over a bluish one? If you have the pool algae challenge, there are perfect solutions to the problem. Read on:
Table of Contents
- 1 3 Ways to Destroy Pool Algae
- 2 Why Is My Pool Water Green?
- 3 What Method Is The Best?
3 Ways to Destroy Pool Algae
Before we proceed, we are going to discuss pool algae and how they are formed.
Pool algae are a plant or plantlike organism that is of the several phyla divisions. They are usually aquatic and contain chlorophyll. They are nonvascular organisms of polyphyletic origin. Algae are that small plant-like organism which usually grows in pool water. They come in three common forms:
- Black algae
- Green or blue algae
- Yellow or mustard algae
1. Green Pool Algae
Green pool algae are the most common swimming pool algae. It takes advantage of the lack of proper sanitation and filtrations to grow. You can find this algae floating freely in your swimming pool causing the pool to turn entirely green.
Green algae can also be seen clinging to the wall of the pool, at the edges and/or at the bottom. You can brush it off easily and make it free-float. The advantage of this kind of algae is that it’s quite very easy to get rid of. You may still have residues of it in little spots of the pool that have poor circulation or are hard to reach with scrubs. In this case, just use some sanitizer of algaecide to get rid of it.
2. Mustard Algae or Yellow Pool Algae
This kind of algae is referred to as the stingy algae. It grows on the swimming pool walls, especially in hidden spots that do not get a lot of sunlight. It’s the second most common swimming pool algae after the green algae. You will sometimes mistake it for sand or pollen that collects in your pool.
Yellow pool algae are quite difficult remove and won’t be killed off by regular doses of algaecide or sanitizers such as chlorine. They get killed when you super shock your swimming pool, else you’ll find yourself struggling with the mustard algae throughout the season.
3. Black Algae
You probably have had a good fight with yellow algae and you think it was hard and tough? Well, the worst is saved for the last! Black algae are the strongest, toughest and the stingiest of all algae, though it may not be very common as compared to the yellow and green algae. This alga is so hard to get rid of because of its strong defense mechanism and its strong roots. This algae forms like little sticky dark or black spots on the walls of your swimming pool.
The visible part of the algae has a protective layer, with which it protect itself and it has strong roots that is capable of growing deep into the plaster of your swimming pool walls. You may still have this strain appearing on the walls of your pool, even if you are taking good care of your pool normally, just like yellow algae, even when you observed all the sanitation procedures and rules. Killing it requires lots of shock and a very strong pool brush.
Why Is My Pool Water Green?
Algae can be found where ever there is water. This is what you need to treat your swimming pool with the proper chemicals to prevent the growth of these stubborn bacteria and to keep your pool looking clean and attractive.
If algae grows in your pool, the main reason is because you haven’t treated it with a sanitizing chemical, such chlorine, or you haven’t treated it sufficiently. Also, if your pool lacks sanitation, and the water in it is stagnant, you’re definitely going to attract algae. This is why it’s important that you ensure that you have good filters and pumps to ensure your pool water is moving. Algae find it very hard to grow in moving water.
Algae also thrive well in dark places where water does not circulate well. Some of these places include:
- Your pool steps
- Under your ladder
- Corners, cracks and crevices
These are great habitats for algae and they feed and multiply easily under these conditions.
So now, having gotten a general understanding of the pool algae, what they are and why it forms, let’s find out how to get rid of them:
Method #1: Destroy Pool Algae using Superchlorination (also known as Shock)
There are 3 different stages of algae in which different amounts of shock are needed, there is:
Algae has three different stages. Each of these stages require different amounts of shock. We have:
- Light green algae
- Dark green algae
- Black green algae
Note that these are not types of algae, but the different amounts categories. Thing is, the more algae you have in your pool, the darker the green color becomes. Your pool can even become black with algae infestation. It’s a very disgusting sight!
Light Green Pool Water
If your pool has a light green color, you need a double shock treatment in your pool to kill the algae. Normally you will need 1 pound of shock to treat up to 10,000 gallons of water. Therefore, to treat a pool with 10,000 gallons or a little less you will be required to add 2 pounds of shock to double shock it. If your pool has a 20,000 gallon capacity, you will need to add a 4 pound bag of shock. And for a pool of 40,000 gallons or less, 8 pound bags are required, and so on.
Dark Green Pool Water
A triple shock is needed if you have a dark green pool. This would mean a minimum of 3 bags of shock per 10,000 gallon pool or less, 6 pound bags of shock for a 20,000 gallon pool and 12 pound bags of shock if your pool is 40,000 gallons in capacity or less.
Black Green Pool Water
If your pool is in a sorry state and is so dark, you need to take extra care to quadruple the shock. The “black lagoon creature” green pool needs quadruple shock to totally destroy the algae. This means that you use 4 pound bag of shock to treat a 10,000 gallon pool or less. If your pool has a 20,000 gallon capacity or a little less, 8 pound bags of shock will clear the algae and for a 30,000 gallons pool or less, ensure you use a quadruple shock of 16 pound bags, etc.
Note: If your pool has a vinyl liner, ensure you dissolve every 1 lb. bag in a bucket of water before putting it in the swimming pool. This would prevent the bleaching out of your liner by the shock. Also, if yours is an automatic chlorinator, DO NOT pour the shock through the skimmer. This is because of the Calcium Hypochlorite content in the shock. If mixed with trichlor (which by the way is always present in most chlorine tablets) it will create a dangerous explosive green gas. And do not forget to always shock at night. In direct sunlight, chlorine burns off one Part per Million (1 PPM) every hour, causing the break-point oxidation in the chlorine to drop below the level required to kill algae.
Method #2: Floc Your Swimming Pool
Floc (or Flocculant): This is a chemical that gathers all the small particles in your pool (including algae) and sediments them to the bottom of the pool. All you now do after the particles have settled would be to vacuum them OUT of your pool. Although this method is more cumbersome and time consuming, if done correctly, it gets the job done, and quickly disposes of the algae.
How to Floc Your Swimming Pool:
If your filter has a multi-port valve, shut off the pump and turn the valve to “Recycle” or “Recirculate”. This will make the water to stop flowing through your filter. It will now spin the water around, thereby helping the mixing of the chemical within.
Add the dosage of Flocculant recommended to your pool. Floc comes in powder and liquid form. Ensure you check the directions for application and apply the right dosage for your swimming pool size.
Make the water circulate for about 2 hours so that the chemicals get mixed in fully, then switch off your pump and allow it sit overnight. The chemical will use the time to bind the particles together make them settle at the bottom of the pool. You should wake up in the morning to see a nice healthy cloud of particles at the bottom of your pool.
Start your manual vacuum cleaner. But before your turn the filter on, be you have your set your multi-port valve to “Waste.” You don’t want the thick water going through your filter when the thick cloud have been vacuumed OUT of your pool because your filter may not be capable of clearing the water out that quickly, and it will make the cloudy green water to shoot back into the pool via the return lines. Also connect the backwash hose to its waste port and channel the hose to where you want your dirty water flow to.
Turn on your garden hose and add it to the pool while you vacuum. It’s usually best when the garden hose replaces the water with clean water as the dirty one is being vacuumed out
Vacuum the bottom of your pool slowly. The water you’ll be sucking out will be thick and dirty. And it will start kicking up debris as you vacuum across the pool floor. Once it gets so cloudy that you’d hardly see, shut down the pump and let it sit for some hours to resettle, then continue vacuuming. You may have to repeat this several times, depending on the dirt level of the debris you need to vacuum. Its hard work.
All you need to do basically is, buy this cheap chemical, get your hands dirty and work, and you would have cleaned up the pool completely in one day.
Once the vacuuming is done, it is highly suggested that you double shock your pool to ensure you have destroyed and removed all the algae.
Method #3: Use Swimming Pool Algaecide
Algaecide is normally used as a preventive measure. But some algaecides contain b14 or metals such as silver or copper, which can kill algae. You can add the algaecides in large doses, depending on the brand. You can also mix it with shock to achieve a great result.
Algaecides are best used as a preventive. A few ounces every week can prevent algae from growing in your swimming pool. This is because it can be more expensive to kill algae using. You should also know that too many metals to your swimming pool causes the water to stain.
“Poly quats” are recommended preventive algaecides that can kill algae. Be warned however, that large doses of it can cause your water to foam excessively.
In summary, there are algaecides that can kill algae. Contact your local pool store for the algaecides that kill, or ensure you read the specifications carefully if you are buying online.
What Method Is The Best?
All the methods mentioned here work well. Any pool store or website will usually promote one of these and may end up confusing you, if you are unsure of the best method that suits you.
I will personally recommend method 1. It’s affordable and easy, and KILLS all the algae.