MGK Pool Service

How to Clean Green Pool Fast? – Easy Instructions

Best way to clean green pool in 24 hours!

  1. Shock the Pool: Before you can clean a green pool, you have to kill the algae. This requires a lot of chlorine. I usually use 5-10 gallons, depending on the size of the pool and how thick the algae is. You will know you used enough chlorine, if within a short time the green starts to lighten in color.
  2. Brush the Pool: You need to brush the entire pool. Brush all the algae off the walls and floor, and get it mixed into the chlorine.
  3. Wait: Yes wait with the pump off. you want all the algae to die and fall to the floor. Running your circulation system (pool pump), will stir up dead and live algae, and keep the water cloudy.
  4. Vacuum the Pool to Waste: Filters are not designed to catch massive amounts of dirt, they are designed to maintain clean pool water. So by-pass the filter and pump what you are vacuuming up, straight to waste. You will lose a lot of water if you do not do this fast. Most filters have a multi valve with a waste setting.
  5. Filter the Pool: You can vacuum dirt off the walls and floor, but you can’t vacuum what is floating! Floating debris/particulate/dirt, has to be filtered. The best filter for this is D.E (Diatomaceous Earth). If you have a good filter, and have followed the steps above, your pool should be clear in 24-48 hours. You may need a light vacuuming even after the pool clears. Some dead algae that is not caught by the filter, will continue to fall to the floor.

How to clean green pool

Extreme Cases of Green Pool

If you have an extreme case, with a ton of algae and leaves on the bottom of the pool. As in cases where the pool has been closed for the winter, or for multiple seasons, or even worse, the cover has fallen in. You should attempt to vacuum the pool to waste before proceeding with the above instructions.

If there is to much debris, and you can not vacuum. You have no choice but to leaf rake the entire pool with a leaf net. Continue removing debris with leaf net until you can make a pass, and only catch a few leaves in the net. You may have to let the pool settle, and then leaf rake the entire pool again.

Vacuuming Pool To Waste

This means we are not going to try and filter the water, we are going to pump it onto the lawn, or nearby wood line. This is a recommended procedure when opening a pool with a mesh pool cover. Algae grows in pools with mesh covers, and dirt sifts through the cover as well. Again, filters were never meant to clean super filthy water.

I use a side vac (pump), meaning I bring my own equipment. I use a  Hayward 1.5 HP Super Pump, a 30, or 40 foot I-Helix Vacuum hose, a vacuum head with bristles, and relief valves. Many pool filters have a waste setting, but you run the risk of clogging the skimmer line with acorns, broken pieces of tile, small rocks, etc… With a hose connected right to the front of my super pump, I don’t run the risk of damaging the customers plumbing.

You can see an example is this, in the short video below. When customers are not around to see how bad the pool looks under the cover. I like to shoot a quick video to show them, and justify my bill! I usually charge 150.00 for a side vac.

The pool in this video, had minimal leaves, so I was able to vacuum the heavy algae and dirt straight to waste. I usually run a garden hose into the pool while vacuuming to waste, even in cases where the pool is over filled.

In this next video, I narrate as my helper Hugo does the vacuuming. This pool had a very green bottom. If someone was to come and brush this pool, they would stir this mess up, and then the only way to clean this green pool, would be by filtering it. That means cleaning the media in the filter, countless times over the course of 2 weeks.

With this method. My customer (Harry), will have a clean and clear pool by the next day! Watch the next short video below to see complete set up.

It is this process that makes people think I’m a miracle worker. You can see the pool turning to blue, as the algae and sediment is pumped directly out of this pool. If you want to to get your own equipment. I make recommendations just below.

Hayward Super Pump: I use a 1.5 HP because I like the extreme suction power. But you could use a .75 HP, or a 1 HP Super Pump. The cool thing about this pump, is that it runs on 110V or 220. I put the jumper on 110V and wire a long extension cord to a water proof switch, right on the side of the pump. This way I can power it in any yard I go into. You can often find cheap used ones on Craigslist, or the cheapest place I’ve seen them is on Amazon.

Vacuum Head: I use this one because of it’s special design. I keep a few of them on my van. The trick is to cut the bristles of in 1 inch increments. On mild green pools i use my head with only four cuts, for heavy algae pools, I use a head with 6-8 cuts. Cutting the bristles prevents the vacuum head from getting stuck to the bottom of the pool.

I-Helix Vacuum Hose: This is the best vacuum hose on the market! I only use it on the vacuuming side of the pump. I use a cheap hose for the waste side. I actually sell this hose in my online pool store.

Obviously you will want a good service pole too. but I am sure you have one. The last thing I recommend for professional, and I like to use for pools with lots of leaves, is this debris pot. I hook it up between the vacuum hose, and the front of the pump. It helps me to keep vacuuming, instead of constantly stopping to clean the small basket of the super pump.


If you want to clean a green pool fast, remember filter are not made to do it. So kill algae, wait, and vacuum to waste… Then filter the pool constantly, monitoring filter pressure as you go.

Two final pieces of advice and information. 1st. When vacuuming to waste, keep an eye on the waste water, you can easily flood the neighbors, or even your own basement with all the water you pumping out! 2nd. For tough jobs, I often bring a DE filter, even if the customer has a DE filter. People with cartridge filters should clean them often, and people with sand filters will just have to wait longer for cloudy pools to clear. It’s not that you didn’t do everything right, sand filters just don’t filter small debris well.

*Bonus Tip: Maintain a chlorine level at all times, no lower than 2PPM while cleaning a green pool.

If you have any tips or advice to add, about how you clean a green pool fast, please share them in the comments below.

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