Pool Turned Green After Adding Salt

[steveoFresno]

Hello all,

So I'm having a party tomorrow and it seems I've turned my pool green today (of course!). This is an approx. 3 month old pebble pool, which I've successfully managed thus far using the TFP method. Since startup, I've added only liquid chlorine and acid, with the exception of using trichlor while on vacation once. The water has been clear blue with no problems.

I recently decided that I will add a SWG, which I have not yet done. In the mean time, I decided to add salt to about 2,000 ppm just for the potential water-feel benefits, since I was going to add salt anyway once I decide on a generator. I added 400# (according to Pool Math) of Clorox pool salt and brushed until it dissolved, which it did quickly. About 20 minutes later, the water is clear, but green-tinted. The MSDS lists only sodium chloride. Thoughts? Advice?

FC: 8
CC: 0.5
pH: 7.7
TA: 80
CYA: 50
Salt 3,000 (seems dissolved, but may not be fully mixed)
CSI: -0.14
Temp: 86

 

[Richard320]

Clorox salt? I guess you're number 3

It may go away or you may be hunting for some sequestrant. See also Pool School - Metals in the Water and Metal Stains

 

[steveoFresno]

Thanks, Richard320.

Update:
Though I don’t have proof, I subscribe to the theory that Clorox salt is contaminated with iron. As my pool turned green, I somewhat-reflexively added liquid chlorine. As the pH increased, so did the green tint. I took a water sample to the pool store. They were out of iron test strips, but said there was no copper in my water. They said my other numbers looked great and, to my surprise, they didn’t try to sell me anything.

In case it helps anyone else who encounters this problem, here’s what I did:
I was torn between adding a sequestrant or seizing the opportunity to possibly capture the iron while it was precipitated. The sequestrant could possibly have made the water cloudy for my party and adding it would mean that I would be leaving the iron in the pool. My pool has brown tones in the tile and pebble, which made me slightly less worried about staining, so I opted to hold off on the sequestrant, I added cellulose fiber to my cartridges, and I ran the filter overnight, at cleaner speed, with all valves open. The pool was sparkling blue this morning. I took the filter apart and, sure enough, the cartridges were a deep rusty yellow color (yellow water + blue in the pebble = green water).

So, assuming it was iron, and being cognizant of the possibility for staining, it does appear that iron precipitates can be successfully filtered. This might be helped by the small-micron filtering capability of cellulose (which I will be using from now on because my water has never looked this polished).

 

[pabeader]

You are a lucky man!! My iron wouldn't stay in the water for me to filter it out So glad it worked out for you!!

 

[YippeeSkippy]

WOW! SteveinFresno- you are one smart cookie! That really was a good idea (and brave, considering you had a party coming up)

Clorox products have been on my verbotten list for a while now. Too many instances of contaminated salt problems along with their copper laden products... this just adds more references for me. Thanks.

Maddie

 

[GamecockTim]

I have the same filter, but how did you add cellulose to your cartridges?
How much did you use and where to get it? Any downside to doing this?

 

[YippeeSkippy]

I have the same filter, but how did you add cellulose to your cartridges?
How much did you use and where to get it? Any downside to doing this?

I can't answer re: that filter, but its Polyfil, a pillow and toy stuffing product found in hobby stores.

Maddie