Added Soda Ash to get ph up and pool went cloudy and green

[PhillipMSchwartz]

35K gallon vinyl pool
cartridge filter
chlorine ( no SWG )
Taylor K-2006
heater

On Sunday, I tested the water and everything was in normal range ( I don't have the exact measurements, I typically don't save them if they are in normal range ) except for ph, which was 7.0 . This made sense because we had a bunch of rain in the northeast and our rain is typically acidic. I added about 2 lbs soda ash ( Pool Math said 39 oz , I like to err on the too little side ). I'd read that soda ash can make the pool cloudy, so I wasn't that concerned at first. However, it's Tuesday and now I'm fighting a cloudy, green pool that was crystal clear before the soda ash.

 

[Texas Splash]

However, it's Tuesday and now I'm fighting a cloudy, green pool that was crystal clear before the soda ash.

That could just be a coincidence. Cloudy and green sure sounds like algae. It really would help us to see a full set of water results from your K-2006.

 

[PhillipMSchwartz]

A Google search pointed out to that algae grows in higher ph. Got some ph down ( sodium bisulfate ) and added it last night, ran filter all night. Free chlorine was no longer fighting with the higher ph I guess and was able to do what it does. Pool is blue and clear this morning. Interesting that the chlorine was "losing the fight" with algae when the ph was high. Will measure water in a bit.

 

[mknauss]

pH effect on chlorine effectiveness is muted with CYA in the water.

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...

www.troublefreepool.com

 

[Texas Splash]

Even though you appear to have had some favorable progress, I'd watch it closely. Maybe even do an Overnight Chlorine Loss Test to rule-out algae. In the future, we recommend muriatic acid to lower pH. Other dry acid-type products tend to add sulfates which can be problematic over time. Have a good day.

 

[PhillipMSchwartz]

Muriatic acid makes me nervous.

 

[Texas Splash]

Muriatic acid makes me nervous.

Understandable. MA deserves respect for sure. But careful attention to wind direction and not splashing are key. Besides the full strength 31.5% MA, there is a 15% strength as well which some people use who are a little concerned about the volatility of the full strength. Your call either way, just wanted to ensure you knew.