Clear to Green within Minutes

[nbjerke]

Hey all - 6 year pool owner but we just had the liner replaced in our 28' round. We filled with 6000 gallons of city water but that had to be trucked in to just set the liner in place. The rest was filled through our well (20300 gal total). Yesterday afternoon I started up the pump for the first time, filtering is done through an 18" sand filter. It cleared up the little bit of cloudiness in the pool throughout the night and I figured today would be a good day to start the chemical treatment. I'm planning on SLAMing the pool but wanted to make sure that this will help as the initial dose scared me.

I put in around 2.5 quarts of 12.5% bleach plus a little bit of ph reducer as it was reading high at 8.4+. My full testing kit has not arrived yet (TP-100) so I don't have full numbers yet. Chlorine went to 5-7 or so which is what I was expecting but suddenly and within minutes the water started turning green. A couple hours later now and the PH is still a little high and chlorine stayed about the same but the color intensified more. I can still see the bottom but it just went to straight green color through the water.

Our water does seem to contain a lot of iron, toilets and showers are stained and its almost undrinkable (taste only). The old liner even had some pockets where it stained brown and we couldn't get it out. Would this be the cause of the color? If it is do I need to worry about correcting this first and then worry about SLAMing the pool? Whats the best way to correct it?

Any help is greatly appreciated. I can normally balance everything out on start up within a week but I never started with fresh water like this. Pictures from yesterday and today included for reference. Ignore the wife, she wanted to jump in yesterday against all my advice..

 

[JVTrain]

Metals can certainly present themselves as green/yellow when they are in the pool. Especially at lower pH levels when they are dissolved in the water. At higher pH, they tend to precipitate out of solution and are not visible. When you lowered the pH, the iron dissolved and became visible. If the problem persists, you might have to use metal sequestrants to keep the metals in solution and prevent staining. But they have to be added routinely, not a one time fix. If it were me, I'd do everything I could not to use the well water that contains metals as it will always be an ongoing problem. It can be managed with pH and sequestrants but for the long run, you would have been better served filling with city water as much as possible.

 

[jblizzle]

Welcome to TFP!!!

Joel, I think you got that backward ... the metals appear in the water at higher pH levels and stay clear in solution at lower pH levels. {although now you have me doubting myself }

The metals turn the water to yellow/green when you added the bleach which raises the pH some.

Hopefully a lot of the metal will filter out, but as said above, you likely will need to start to use sequestrants. See: Pool School - Metals in the Water and Metal Stains

 

[JVTrain]

Welcome to TFP!!!

Joel, I think you got that backward ... the metals appear in the water at higher pH levels and stay clear in solution at lower pH levels. {although now you have me doubting myself }

The metals turn the water to yellow/green when you added the bleach which raises the pH some.

Hopefully a lot of the metal will filter out, but as said above, you likely will need to start to use sequestrants. See: Pool School - Metals in the Water and Metal Stains

Dang it, you're right! My brain has been swirling around the drain too long today! HIGH pH makes the metals visible, LOW pH makes them go back into solution. Thanks for the gentle nudge, J.

 

[nbjerke]

I just backwashed as well just to see what the filter was pulling and I'm hoping that a lot of this will filter out... solid brown. I'll keep working the PH down and see if that helps some with the clarity otherwise we'll try the sequestrant route. Thanks everyone!

 

[jblizzle]

I am not 100% sure on the following advice: You may not want to lower the pH too much right away so you can get more of it filtered out.
Although there is a risk of pool staining if you leave the pH high without sequestrant.

 

[nbjerke]

I am not 100% sure on the following advice: You may not want to lower the pH too much right away so you can get more of it filtered out.
Although there is a risk of pool staining if you leave the pH high without sequestrant.

I just checked the pH again, we're at 7.9 or so. Do we think that would be low enough to let it sit and just try to SLAM and filter for a couple days?

 

[duraleigh]

I don't think I would SLAM that pool. It seems pretty certain metals are staining your pool and SLAMming really doesn't address that issue.

Since your iron has precipitated, I would tend to lean with jblizzle and see if you can get as much as possible out.

I think if it was me I would keep that pH right about where it is and let the filter catch that iron. You really need to think about finding another resource for water as that iron will haunt you as long as you pull from that well.

 

[jblizzle]

Yeah, there is no reason to SLAM the pool or elevate the FC higher than recommended depending on your CYA level: See FC/CYA Chart.

 

[nbjerke]

So filter and sequesterants it is?

 

[jblizzle]

No sequestrant yet ... try to filter as much out as possible.