What caused my new pool water to turn green?

aumfc

Well-known member
Apr 16, 2023
51
Pelham, AL
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
Our pool was plastered in white on Monday, 4/10. We filled the pool over about a week (due to low volume) from our well that passed through pH and iron filters. The water after the filters tested at 0 for everything other than a little hardness and 7pH.

The water was clear other than dirt and pollen that had accumulated over the last couple of weeks. We tested it with the strips the pool guy gave us and everything read normal every time. After plaster, when the pool guys turned on the pumps, they added some muriatic acid to lower the pH. The pH has read fine in the week since.

The pool builders finally had someone come out late yesterday afternoon to vacuum and clean everything. After he left, this is what the water looked like. The lights are white.

pool green water 4-26-2023.jpg

Today it's been raining, but this is what it looks like now. Still green.

pool green water 4-26-2023-2.jpg

What would cause this and when will it clear up? Or, what needs to be done to clear it up?

Thanks.
 
What did they add to the pool?
How much?
Do you have any test results from one of the recommended test kits that you can share?
Fc
Cc
Ph
Ta
Ch
Cya
Test Kits Compared
I suspect you have a metals problem (likely iron from your well water) that showed itself when chlorine was added.
Do you know if a sequestrant was added upon filling?
How do you chlorinate the pool?
 
First things first, please order a reputable test kit. Either a Taylor K2006-C or a TFTestKits.net TF-100/TFPro. If pool is equipped with a salt water chlorine generator, please purchase either the K1766 in addition to the K2006-C or just buy the TF-100 Salt/TFPro Salt.
 
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The cloudy green water looks like algae soup.

Iron green water will be sparkling clear.

You really don’t want to SLAM Process a new plaster pool for at least the first 30 days.

Get one of the recommended test kits as the SLAM Process is likely in your future.

How are you chlorinating your pool?
 
The cloudy green water looks like algae soup.

Iron green water will be sparkling clear.

You really don’t want to SLAM Process a new plaster pool for at least the first 30 days.

Get one of the recommended test kits as the SLAM Process is likely in your future.

How are you chlorinating your pool?
It's clear.
 
What did they add to the pool?
How much?
Do you have any test results from one of the recommended test kits that you can share?
Fc
Cc
Ph
Ta
Ch
Cya
Test Kits Compared
I suspect you have a metals problem (likely iron from your well water) that showed itself when chlorine was added.
Do you know if a sequestrant was added upon filling?
How do you chlorinate the pool?
I will test the water with a better kit, but it's likely iron. How do we fix that?
 
How do we fix that?
Get some polyfill. Put some in the skimmer and rinse it out when it gets full. You can also put polyfill in a separate bucket and pull water through that which will then go back to the pool. The more you filter now the better.
 
Since you are on a well, we can be quite confident you have an iron issue. The link below is one of my FAVs. When you update your signature, be sure to also include that you are on a well. When you get your test kit, add that too.

 
Get some polyfill. Put some in the skimmer and rinse it out when it gets full. You can also put polyfill in a separate bucket and pull water through that which will then go back to the pool. The more you filter now the better.

Thanks. The pumps are running. The pool is 35,000 gallons and has 2 skimmers and 2 pumps. Each pump has a filter on it. Everything goes back through a heater.

I can stuff the two skimmers with the polyfill. Should I do more? What is the quickest way to clear it up, that won't also cost me an arm and a leg?

Is the water swimmable as it is?
 
I can stuff the two skimmers with the polyfill.
Yes
Should I do more? What is the quickest way to clear it up, that won't also cost me an arm and a leg?
You can also rig up a bucket with it like in the articles posted.
This is the quickest & cheapest long term solution. Polyfill is a few $ a bag or free if you have old pillows.
Is the water swimmable as it is?
Hard to say without test results.
 
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There are 2 Jandy variable speed pumps with a pre-skimmer going into them. Can I stuff the polyfill in those pre-skimmers as well, without causing any issues? They have a clear lid that you take off to empty the bucket, so I have easy access to getting the fill in it.

This would be the fastest and cheapest way to get the water filtered quickly.
 
Yes

You can also rig up a bucket with it like in the articles posted.
This is the quickest & cheapest long term solution. Polyfill is a few $ a bag or free if you have old pillows.

Hard to say without test results.

The pool test strips we have are all "good" according to my wife. (I'm color-blind so those strips are tough for me)
 
I might have missed it, but at any point has chlorine been added to the pool? If not 16 days is a long time for water to sit without chlorine, and almost guarantees algae.
 
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I might have missed it, but at any point has chlorine been added to the pool? If not 16 days is a long time for water to sit without chlorine, and almost guarantees algae.
It was clear an hour before the pool guy came and added shock and chlorine. An hour after he left it was green.
 
Yes

You can also rig up a bucket with it like in the articles posted.
This is the quickest & cheapest long term solution. Polyfill is a few $ a bag or free if you have old pillows.

Hard to say without test results.
Can I put the polyfill in these pump debris baskets?

20230427_201654.jpg

What about in the large filter itself?

20230427_201703.jpg
 
No- stick with the skimmer baskets only.
You don’t want it to accidentally end up in your plumbing, filter internals, or pump impellers.
Change it out/wash it out as it accumulates the iron.
 

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