Clear Green Pool-Help Please

[kdoonan]

I've been a BBB user for 3 three years with great success. A friend just bought the same pool and it's green. She started with a bunch of store bought chemicals and the pool went green. It was clear when she filled it. I went with my TFP100 Kit yesterda and am trying to help her. I could use some advice. The pool is crystal clear but it's green in color. BTW. The weather in MA today is a heat index of 105 so I expect the chlorine will burn very quickly.

Pool: 6000 gallon vinyl
Filled: About 4 days ago w/well water

Numbers today:
FC 21
CC 0
pH 8.2
T/A 150
CYA 0-10

When I went yesterday the numbers were:
FC 9.5
CC 0
pH 6.0
CYA 0-10

She shocked the pool yesterday before I arrived. I took the reading about 5 hours later. She followed the pool calculator told us to do but we're still green.

Could someone please offer some advice. My sense is she needs some stablizer but at this point I thought I'd ask before having her dump anything else in there.

Thanks so much!

 

[Suziqzer]

I would wonder if it has any metals in it. Copper can cause a green color. I would keep the chlorine levels in the pool and wait about a week to check the cya again so you know how much she's already added and go from there w/cya.

In the mean time I would have the water tested for metals to see if that might be your problem. Metals in the water can stain your pool as well as people's hair

Looks like too that her ph is too low so you should get to work on that as long as her chlorine levels aren't too high.

 

[kdoonan]

Suziquzer, I thought the pH was too high today. Do you think 8.2 is low? Are metals are more probable given well water? The chlorine levels are high because we were looking to shock whatever is in there. The CYA is also low, at less than 10. I didn't retest it today though. How quickly does it change?

 

[lightingguy]

You would expect a FC of 21 with low CYA to kill pretty much anything and make the water cloudy. Do you have a sense of how much CYA was added? It may not be showing up yet in the test.

The combination of well water, clear green and low PH does sound like copper.

The PH is closer to 6 not 8.2 At shock levels the PH test gives a false high reading.

Personally I would think there was a chemical addition mistake from the pool store - too much acid which caused the copper to turn the water green. A ph of 6 is really aggressive low.

 

[kdoonan]

I had her hold on the CYA because I really wasn't sure what or how much was added ahead of my involvement. Yesterday there was virtually no CYA. Would the number change much since yesterday? So even if the pH say 8.2 today do you think yesterday's reading is correct and today's is not? How do we know how much borax to add to boost the pH if the reading is not accurate?

 

[lightingguy]

I would assume that the PH reading is more accurate at a FC of 9 than a FC of 21.

If it were me - I'd just let the sun burn off all that chlorine today (which it will very quickly without CYA) and test this evening to get new results.

If the PH comes in super low again and the water is still clear and green copper sounds as likely as algae. Then you can pool calc the proper amount of borax to get the PH back into range.

 

[kdoonan]

Thanks lighting guy. Seems like good advice. How do we test for copper and what is the fix for it?

 

[lightingguy]

Any pool store should be able to test for metals.

There are metal sequestrants you can use and strategies for dealing with metals if that turns out to be the issue. I wouldn't instantly jump to that conclusion - your situation just sounds suspicious.

 

[anonapersona]

Can she tell you what the pool store sold her, is there a receipt somewhere? Some algaecides contain copper. Math errors can be important if mistakes were made on what to add and when.

 

[amystrz]

Hi. I am the one with the green pool! I went to the pool store and they were convinced it was copper. They told me to add mineral magnet and wait 5 days without running the filter to bind the copper with the magnet. Can I continue to add chlorine during those 5 days so my pool doesn't turn into an algae infestation? Thanks!

 

[kdoonan]

Tonight's numbers were consistent with this morning's test, except the FC dropped to 4

Numbers today:
FC 21 this morning 4 this evening
CC 0
pH 8.2
T/A 150
CYA 0-10

 

[lightingguy]

There is a section in pool school on metals which lists some of the preferred sequestrants.

Your PH is a mystery - perhaps the initial reading of 6.0 was somehow testing error and you've been high all along. If you are confident that your PH is high then it's just a matter of getting it down into range.

At the pool store - did they run a test for metals or just listen to you tell them you thought it was metals? I would go with one of the recommended sequestrants in pool school - but I haven't had a metal issue.

Keep some chlorine in it regardless until you have a course of action.

 

[Bama Rambler]

I'm thinking the pH is an error.

If the water is sparkling but green it's most likely metals. The metals test most likely isn't going to show anything as it's not dissolved if you're seeing it. Use one of the recommended sequestrants or dump the water and refill with non-well water.

 

[amystrz]

Hi All, Thank you for the help.
PH of 6.0 is might be right, we had our water tested in 2006 & 2007 by a lab. Ph measured 5.6 & 5.8, respectively, straight from the well.
Copper was 0.14 mg/L (EPA limit is 1.3), Iron was 0.31 (in 06), & 0.14 (in 07) [EPA limit is 0.30], Manganese was 0.12 [EPA limit is 0.05] So we certainly have lots of metals.

I'm not sure why KDoonan measured 6.0 the 1st time, but we added PH up at the same time we shocked the pool, maybe it hadn't effected the PH yet.
Today the PH is coming down slightly - Looks to be 7.8 with a test strip. {Our kit is on order!!}

The pool store didn't test the water for metals, just heard the story and came to a conclusion. Clearly we should have pushed them to test it.
They sold us Blue Shield Mineral Magnet. We put it in a yesterday, and the water looks to be a lighter shade of green.
The instructions say to let is rest without the filter on for 5 days. So we will see where we are on Wednesday.

Thanks for all the help!!

 

[Bama Rambler]

I would be seriously concerned not running the pump for 5 days. You're surely going to have an algae outbreak unless you can keep some chlorine in there or add some algaecide. Polyquat 60% is what we recommend in special circumstances like this.