Green Swimming Pool Water – Treat It With These 4 Simple Steps!

by T. Duff on March 31, 2011

Lets face it, every pool will experience green water at one point or another. The main mission when this takes place is two fold. The first is how to treat the water as effectively as possible to get it clear again as quickly as possible. The second item that needs attention is we want to make it happen without breaking the bank. If you go down to your local retailer there’s more shocks, phosphate treatments and water clarifiers than one knows what to do with. Not to mention the countless “novelty” chemicals that are available that can cost an arm and a leg!

When treating green swimming pool water, there are 4 key steps that need to be addressed. Let’s dive in!

Treating green swimming pool water step #1: Circulation. Water circulation is an absolute must. You can add all the shock and other chemicals you want, but if water movement isn’t taking place, it won’t change the look of the water. While you’re turning the pool around, run the equipment 24/7. For most standard residential swimming pools, this will allow for about 3 full water rotations. Meaning, that all of the water will have gone through the filter about 3 times.

Treating green swimming pool water step #2: Shock treatment. Ideally, shoot for a granular shock because it has the fastest reaction time. I’d recommend using HTH Super Shock that contains at least 65% available chlorine. The more available chlorine, the more effective (and faster) it will be in the pool water. It’s important to stress that one cannot over shock a swimming pool. Depending on how green the water is, I’d recommend starting with 3-4 lbs of shock, wait 2-3 hours, then check what the water looks like. There’s no need to test the water at this point using a test kit as the results will be meaningless…regardless how much “free chlorine” it’s showing present.

Treating green swimming pool water step #3: Filtration is key. The more effective the filter is throughout this process, the faster the water’s going to get clear again. The best way to ensure this is taking place is to backwash/clean your filter several times a day. You cannot over-backwash your filter. If you’re using a DE or sand filter, place the multi port valve in the backwash position and let it run for around 90 seconds or until the water is clear. This may take a bit longer depending on the duration of time between backwashes. If you have a cartridge filter, remove the dome of the filter (typically, there’s a band clamp that needs to be removed), lift the cartridge filter(s) out of the filter unit and thoroughly clean it.

Treating green swimming pool water step #4: As the water begins turning clear (still may be cloudy, but blue (not green), begin administering a quality water clarifier. This will speed up the process to getting clear water again. I’d recommend adding it the first time immediately once you notice the water is blue and not green, then again about 12 hours later. During this process continue running the equipment nonstop. During this time you should also be stabilizing the pH and Total Alkalinity levels. I wouldn’t worry about testing or adjusting free chlorine as it’s likely going to be elevated for a few days while the water adjusts, but it is important to test and adjust your pH and TA levels.

I hope you’ve enjoyed these 4 steps on getting your water cleared up as quickly as possible. Using this system, it’s possible to turn your green swimming pool water around in 48 hours or less!

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