Updated at: 16-06-2022 - By: Sienna Lewis

Is your pool covered in algae? That’s not an isolated incident. As the most prevalent problem faced by most pool owners, green algae is followed by tenacious black algae (black spot) and mustard algae, respectively. What causes them? How to prevent them? And what can you do to prevent the issue from returning? We’ll cover all three in this article. If you prefer videos, here is one of our lead technicians’ take on the best approach to get rid of algae in your pool. 3, 2, 1… Go for it!

What is pool algae?

Pool water is full of tiny plant-like organisms known as algae. In general, there are three types:

  • Algae, whether green or blue
  • Algae known as mustard or yellow
  • Ascomycete

1. Green Pool Algae

Because of the high pH and inadequate sanitization and filtration, green algae is the most frequent type of swimming pool algae. Algae floating in or on the walls of your swimming pool can turn the water green, which can ruin the appearance of your pool as a whole. Brushing it off and letting yourself float away is a piece of cake. This sort of algae is easier to remove, which is a positive thing. A small amount of sanitiser (chlorine), hydrochloric acid, or algaecide can be used to get rid of it in areas of your pool that have poor circulation. However, a little algaecide would go a long way in making things a lot easier! Water TechniX, of course, is the chemical we rely to get rid of pool algae!

get rid of green algae in your tank - YouTube

2. Yellow Pool Algae or Mustard Algae

In parts of your swimming pool that don’t get a lot of sunlight, yellow algae grows. As the second most common algae in a pool, it is often mistaken for sand or pollen that has accumulated in the water. You can’t get rid of this algae with a standard dose of a sanitiser like chlorine or an algicide. Swimming pools must be “super-shocked” with a high concentration of chlorine and acid in order to get rid of the fungus. Check out our comprehensive tutorial on how to shock a swimming pool for more information.

3. Black Algae

Your swimming pool’s wall will appear to be covered in dark black blotches due to the presence of this algae. It’s not as difficult as you might imagine to get rid of yellow algae from a swimming pool. Black algae’s powerful defense mechanisms and deep roots make it difficult to eradicate. Roots penetrate deep into the plaster of your pool walls and are protected by a thick layer of plaster. You’ll need a powerful pool brush and a lot of shock to get rid of it (chlorine and acid). Black Spot Remover, for example, is a concentrated chemical that can be used to remove black algae.

Why Do I Have Green Pool Water?

Most of the time, the main cause of algae in your pool is that it hasn’t been properly disinfected with sanitizing chemicals like chlorine or that the pH level is too high. Algae’s diet consists entirely of water with a high pH level. If you don’t keep your pool clean, you’re more likely to see algae forming in the water. Keeping the pool water circulating with a filter and pump is essential. Algae have a hard time growing in flowing water. Dark regions with little water flow are also ideal for algae growth.

  • You have a ladder that goes under your pool.
  • On the steps of your pool
  • Each and every nook and cranny

So now that we have a general understanding of what pool algae is and why it forms, we must destroy it!

How Do I Get Rid Of Pool Algae?

Method #1: Get Rid of Pool Algae by Shocking Your Pool Water

So, now that we know what pool algae is and how it occurs, it’s time to eradicate it!

  1. Apply a large dose of liquid or granular chlorine to disinfect your swimming pool. Stabilized chlorine should not be utilized.
  2. Hydrochloric acid or pH Down Tablets can be used to lower pH levels in the body’s tissues. Chlorine’s effectiveness will be improved as a result of this.
  3. For the shock treatment to be evenly distributed around the pool, leave the device running for at least 24 hours after turning it on. Remove any accumulated dirt from the pool filter and clean it.
  4. Observe the water for two to three days, then retest and rebalance as needed. Return the filtration system to its normal operational mode.

The Water TechniX Green Pool Bundle, which includes our specially formulated Water TechniX Tri-Shock, is an option for those who don’t want to go through all of the stages above. You won’t ever have to worry about acquiring a green pool again with the Tri shock because it contains some of the most powerful shock chemicals available. Just follow the directions on the package and you’ll never have to worry about your pool shocked again!

Different Colors mean different stages of algae growth

Different doses of pool shock are needed during different phases of algae growth, which are:

  • Algae that is a pale green color
  • Algae of a dark green color
  • Algae that is black and green in color

All of these points are further discussed below.

Algae Control - YouTube

Light Green Pool Water

Shocking your pool is necessary if your water is a light green color. If you have a high pH level in your water, algae thrives and chlorine is less effective. Hydrochloric acid can be used to reduce your pH. Begin with 1 to 2 liters of water. It is incredibly toxic and harmful, so be careful when putting it in the pool. Vinyl-lined pools should only have one liter of chlorine added every 24 hours because of the increased sensitivity to strong chemicals. In addition, chlorine shock is required for your pool. Use two cups (400 grams) of unstabilized granulated chlorine or three 15-liter tubs of chlorine (only 20% chlorine by volume). Your pool should be disinfected by adding 2 to 4 bags of salt and running your chlorinator at 100% for a couple of days to bring the chlorine levels up. You may need to replace your electrode if after a few days of using your chlorinator at 100%, there is still no chlorine being created or your ‘low salt’ sign is on. An electrode has a life expectancy of three to five years on average. Your cartridge filter or sand filter will also need to be cleaned or backwashed, making sure that all of your skimmer baskets and pump baskets are empty. Make sure to add 500g to 1kg of Stabilizer/Cyanuric Acid/UV Blockout to your pool once it’s sparkling to keep the chlorine from evaporating.

Dark Green Pool Water

If your pool water is a dark green color, you’ll need to use a higher concentration of acid and chlorine. Add 2 to 3 liters of acid and 2 to 3 cups (600 g) granular chlorine over 48 hours. Also, dark green water may be a sign of stagnant detritus at the bottom of the pool, which needs to be removed before you begin dosing the pool. Before manually vacuuming the pool, make sure that all of the leaves and other debris have been removed from the pool using a leaf shovel and the proper length of hose (9m, 11m, or 15m).

Black Green Pool Water

x3 of the “Light Green Pool Water” dosage, as described above, will be required if you have a Creature from the Black Lagoon green pool. It may take 2 to 3 weeks of filtering, cleaning, and filter backwashing to finish the clean-up procedure completely. Static material, such as leaves or a critter that got caught and never made it out of the pool, will almost probably be present in the water before it is dosed, making cleaning the pool before doingsing a necessity. A leaf shovel is needed to remove all of this before physically vacuuming it out of your swimming pool with a vacuum head, the right length hose, and a telepole. You should always dilute chemicals going into a vinyl-lined pool in SEPARATE tubs of water (we don’t want any chemical reactions happening here) in order to avoid damaging the liner and ruining the entire pool experience. Is there anything you’d like to know about how to vacuum your pool manually? Here’s a how-to on manually vacuuming your pool.

Method #2: Floc Your Swimming Pool

Small particles in your pool, such as algae, can be removed from the water by using a flocculant (or flocculant). Vacuuming the pool is your responsibility once all of the debris has settled to the bottom. If done correctly, this procedure can take a long time and require a lot of effort, but it is extremely effective at getting rid of algae. As a precaution, we do not advocate this procedure if you are using a cartridge filter. You’ll have to replace the filter cartridge element if you do.

Lo-Chlor Maxi Floc Plus 1L Flocculant – Pool Chemical

Step-by-step guide on floccing your swimming pool:

1. Set your filter to “Recirculate’ or ‘Recycle’.

Shut down your pump and select ‘Recirculate’ or ‘Recycle’ on your filter’s multi-port alve. This will halt the flow of water through the filtration system. This does little more than stir the chemical into the water.

Liquid and powder forms of Floc are both available. Make sure you follow the guidelines for the correct dosage for your pool’s size.

3. Let the water circulate for at least two hours.

After ensuring that the flocculant is thoroughly mixed in, run the water for about two hours before turning off the pump and letting it sit overnight. Particles will begin to stick together during this time, resulting in the pool’s floor becoming more stable. The bottom of your pool should have a healthy particle cloud when you get up in the morning.

4. Set your vacuum multiport to ‘Waste’.

Connect the hose to your upright vacuum cleaner. Make sure your multiport valve is set to ‘Waste’ before you turn on your filter. You don’t want to put your filter through the thick water you remove from your pool with your vacuum. As a result, if you have a cartridge filter, you will have to change it sooner rather than later because you won’t have this waste choice available to you. If your pool has a cartridge filter, we don’t advocate floccing it unless you intend to replace the cartridge filter element afterward. This can be very expensive, costing anything from $60 to $150.

5. Add your garden hose to the pool and turn it on while you vacuum.

You’ll be wasting a lot of water because you’re vacuuming on the “waste” setting. If possible, use your garden hose to flush out the unclean water as you vacuum it up.

6. SLOWLY vacuum the bottom of the pool.

Using a pool vacuum to remove a thick, nasty sludge from your pool may cause it to kick up debris as you run the vacuum around the pool floor. Shut off your pump and let it sit for a couple of hours to resettle if it becomes too hazy to see what you’re doing. Afterwards, you can resume vacuuming. The amount of debris you need to remove from the vacuum may necessitate doing this step multiple times. After you’ve finished vacuuming the pool, we recommend a double shock of 2 to 3 litres of acid and 2 to 3 cups (600g) of granulated chlorine to ensure that all of the algae has been either cleaned or eliminated. Is there anything you’d like to know about how to vacuum your pool manually? Here’s a how-to on manually vacuuming your pool.

Method #3: Use A Pool Algaecide

Algaecides that destroy algae directly exist, however the most majority are nothing more than a fancy name for chlorine and acid. Algaecides can be expensive, especially if they need to be used in big quantities. Hydrochloric acid dosing and raising your chlorine levels should also work, unless you’re using a specific black spot algaecide for a specific black spot problem. Your swimming pool can be protected from algae by adding 200mL per week. Aside from that, metal bases are commonly found in algaecides, and you don’t want to overdo it with metals in your pool. Staining can be caused by metals in your water.

How Do I Stop Algae From Coming Back?

A pound of cure is better than an ounce of prevention, right? This is a perfect analogy for your swimming pool. You won’t have to worry about the additional costs of trying to revive your pool if you prevent it from becoming infested with algae. Maintaining your pool on a regular basis will help to keep it clean and free of algae. It will take some effort, but the results will be worth it. Do you have a limited amount of time? If you follow our advice, you won’t have to spend a lot of time testing and repairing your pool water. The easiest way to keep your pool water clear of algae is to make sure your pool filters are always working properly!

Which Method Is Best?

We would use Method #1: Shocking the pool every day to get rid of the algae. It’s easy to use this approach because it only requires chlorine and acid, and you can use your filtration system to revive the water. If your pool is in good shape, it may only require a few days, but it’s by far the most straightforward method. The Water TechniX Green Pool Bundle includes our Tri-Shock, which eliminates the need to measure out and mix and match chemicals. Cyanuric acid, which is part of the Tri-Shock, helps to keep your pool clean and clear by extending the protection provided by the chlorine. A clarifying cube is included, which you may use in your skimmer basket to trap the microscopic dead algae particles that cause your pool to become cloudy.

What’s the difference between black and green algae?

Gloeocapsa magma, a black algae, is the most likely culprit if you notice dark streaks on your roof, siding, and other exterior areas of your property. A cyanobacterium known as Gloeocapsa magma can withstand freezing temperatures, wind, and the sun’s severe rays. There are two reasons for this: its black color and hard outer capsule. Gloeocapsa magma’s black pigment allows it to survive in conditions where green algae would be unable to flourish, such as in hot, dry climates. As long as there is adequate moisture, black algae may grow on just about any outdoor surface, even in the midst of the sun. This dark growth is difficult to remove because it sticks so tenaciously to surfaces. If you have algae on your roof, you may notice black or gray streaks running down your roof. Most likely, cholophyta algae (“green algae”) or cyanobacteriums related to gloeocapsa magma are the cause of any green staining on your deck or siding. As with plants, chlorophyll is the pigment responsible for the green hue. Algae known as green algae grows in wet, partially shaded areas. It grows best on north-facing walls, which have a lot of water but little direct sunlight. Algae that is green in color turns anything it comes into contact with a vivid shade of green and can be unsafe to tread on. Green algae can take over an area if it isn’t treated. *** Wet & Forget should only be used on water features without fish.

How to Fight the 6 Most Common Types of Algae in Your Fish Tank – Aquarium Co-Op

Does algae damage surfaces?

Slippery decks and walkways can be caused by the growth of algae. You, your family, and your guests could be in danger if you do this. As well as looking bad, algae on your roof can wear down your roof’s shingles over time. Your roof will become less reflective and absorb more sunlight as the algae grows. Roofs can absorb more heat if they receive too much direct sunshine. As a result, cooling expenses will almost certainly rise. Lichen, an invasive growth that may cause significant harm to outdoor surfaces if algae and fungus form a relationship, will result if the two organisms work together.

How do I get rid of algae?

You might think that pressure washing is the best way to remove algae. However, the force of the water can cause your shingles to lose their protective granules. Pressure washing can even tear shingles off your roof! Some homeowners also try to get rid of algae by using bleach. Bleach is a caustic chemical that can kill your lawn and plants. It can also rust your downspouts and cause your shingles to shed their protective granules prematurely. Using bleach on algae requires brisk scrubbing and rinsing. This is not only time consuming, but it can increase the wear and tear on your roof.

Pressure washing and bleach aren’t the best options for cleaning green and black algae. Even if you try to remove the algae, it can easily grow back because these cleaning methods don’t effectively attack the full growth. Meaning there are traces of algae left behind, and it can quickly come back. Wet & Forget Outdoor eliminates algae without any bleach, scrubbing or pressure washing. No matter the type of algae you have covering your outdoor surfaces, Wet & Forget Outdoor will take care of it.

It penetrates black algae’s defenses and removes the green algae that can grow on the shaded areas of your roof. Wet & Forget Outdoor Cleaner works with the wind and the rain to wash away green and black algae stains over time. When applying, just saturate the area well, and the algae will gradually come off the surface over the next few weeks. Once applied, the Wet & Forget starts working to remove algae on outdoor surfaces and is designed to wash the dead growth off over time with the outdoor elements. Click here to read about one of our customer’s testimonials on how he used Wet & Forget to remove algae that was growing on his patio. If you have algae that’s leaving dark stains on your roof, clean it easily with Wet & Forget Xtreme Reach™ Hose End.

Roof cleaning with Wet & Forget is easy as you can apply it with your feet firmly planted on the ground. The jet tip nozzle will reach surfaces up to 30′, so you don’t need to use a ladder to get onto your roof. The gentle formula of this roof cleaner will not harm or damage your roofing shingles. The new Wet & Forget Rapid Application Xtreme Reach™ Hose End product makes it easy to apply to hard-to-reach areas and high elevations. For green and black algae on your sidewalk or retaining wall we recommend using the Wet & Outdoor Concentrate.

Simply dilute the concentrate using a 1 part Wet & Forget to 5 parts water mixing ratio in your garden pump sprayer and spray it onto your outdoor surface. If the algae growth is on a planter or steps, use Wet & Forget Ready-To-Use for a quick application. Wet & Forget Ready-To-Use is premixed, so all you have to do is attach the trigger sprayer and saturate your algae-coated outdoor surface. Wet & Forget cleans the surface properly, so you’re less likely to see regrowth.

Most customers don’t see regrowth for up to a year after their application. If you live in the Northern regions of the United States, you shouldn’t see regrowth for a few years! ** When using Wet & Forget on a swing-set, spray the product onto the surface then rinse the surface with water the following day before use.

Application Tips

Pressure washing may seem like the greatest technique to get rid of algae. It’s possible that your shingles will lose their protecting granules due to the power of the water. Your roof could be damaged by pressure washing! Using bleach to get rid of algae is another common home remedy. Your lawn and plants might be killed by the caustic nature of bleach. Moreover, it can corrode downspouts and hasten the loss of protecting granules on your shingles.

Algae must be scrubbed vigorously and rinsed thoroughly with bleach to remove it. This is not only time-consuming, but it can also cause your roof to wear out more quickly than it already is. To remove green and black algae, pressure washing and bleach are not the best solutions. Even if you employ cleaning procedures to get rid of the algae, it will quickly reappear because they don’t get to the root of the problem. In other words, there are still traces of algae remaining, and they might soon return. There is no need to use bleach, scrub or pressure wash using Wet & Forget Outdoor to get rid of the algae on your patio.

Wet & Forget Outdoor can take care of any form of algae that is coating your outdoor surfaces. As it overcomes the defenses of black algae, it removes the green algae that can grow on your roof’s shady parts. This product works in tandem with the elements to remove green and black algae stains from the outside of your home over time. As you apply, merely saturate thoroughly and the algae will gradually come off the surface in the following weeks. After being applied, the Wet & Forget works to eliminate algae from outdoor surfaces and is designed to wash the dead growth away over time. For more information on how Wet and Forget helped one of our customers remove algae from his patio, please visit this page.

Use the Wet & Forget Xtreme ReachTM Hose End to remove algae from your roof and prevent it from reappearing in the future. With Wet & Forget, cleaning a roof is simple because you don’t have to get up on the roof to apply it. With a 30 foot reach, the jet tip nozzle eliminates the need for a ladder while cleaning your roof. This roof cleaner’s mild formula will not harm or damage your shingles. When it comes to applying to regions that are difficult to access, Wet & Forget’s new Wet & Forget Rapid Application Xtreme ReachTM Hose End product is the answer. Using the Wet & Outdoor Concentrate to remove green and black algae from your sidewalk or retaining wall is highly recommended. Spray the Wet & Forget concentrate over your outside surface by diluting it with water in your garden pump sprayer to a 1:5 ratio.

This product can be used to get rid of the algae quickly if the problem is on the planter or the steps. All you have to do is attach the trigger sprayer and wet your algae-coated outdoor surface with Wet & Forget Ready-To-Use. A proper cleaning with Wet & Forget reduces the chance of regrowth. A year following implementation, most clients don’t see a return to growth. In the northern parts of the US, you won’t witness regrowth for several years! ** Wet & Forget should be sprayed onto the surface of a swing set and then rinsed with water the next day before usage.