pH/Alkalinity a little too comfortable?

[throwrug]

Hi all! First I would like to thank you all for the vast amount of knowledge shared on this board.

Here's my question:

I have a 15x26 oval pool, which I'm led to believe is approx 12,700 gallons. Currently the pH is 7.0 and alkalinity is 70ppm. (both per Taylor testing kit) Over the last two weeks I've added approx 8 lbs of baking soda with no noticable change in pH and only a 10ppm increase in alkalinity. Currently pool water is nice and clear but eyes get a bit irritated after a while in the water. I've read soda ash should be used to raise pH... but should the baking soda also? Any input would be greatly appreciated...

Greg

[aylad]

The baking soda is used to raise TA without an appreciable difference in pH. More than likely, the eye irritation is because of the pH, which is at the lowest end of where it should be. We recommend 20-Mule Team Borax (laundry aisle) to raise pH, because it won't appreciably raise alk. Your alk right now is fine...

Welcome to the forum!

[throwrug]

Thanks so much for the quick response. 20-Mule Team Borax will be swimming in my pool later this afternoon!

[aylad]

If you can get the pH to the 7.4-7.6 range, then any pH-related irritation should be relieved. One thing I didn't mention above, though--often eye irritation is due to combined chloramines in the water (most folks blame it on high chlorine levels, because they smell the chlorine--what they actually are smelling are the combined chloramines that cause the irritation). What are the other test levels on your pool water? FC,CC, CYA, and what do you use to chlorinate with?

[throwrug]

As of yesterday, the FC was 2, CC was .5 (down from 2.2 on 6/12/12). CYA I didn't test yesterday. I last tested it on 06/12/12 and it was 40. I can follow up with another round of testing, including CYA today. As far as chlorination, I've been using 3" tabs from Leslies, which are according to the website made of: "99% trichloro-s-triazinetrione, which provides 90% available chlorine". I've also been using a 65% available granular shock to attempt at "breaking" the combined chlorine. It seems to be getting better week by week. (2.2 to .5)

Now that I'm thinking of it, which of the two chlorine tests would be better? I think one was a 25mL test and the other a 10mL test. (Taylor 2006 kit)

Thanks again!

[PoolDoc]

Most of the time, the 10 ml test (0.5 ppm chlorine per drop of FAS) is the best choice. You rarely need to know your chlorine level to the nearest 0.2 ppm!)

[aylad]

The 10 mL test is just fine, and it will make your reagents last a lot longer. If your CC has been over 1 ppm, then you need to shock the pool, because that's probably creating more of the irritation than the pH was. With a CYA of 40, then you need to raise your chlorine level to 15 ppm and hold it there until the CC goes to zero, and until you can go from sundown one night to just before sunup the next morning without losing any chlorine.

Janet