"Great Value" Bleach raising pH?

[bottomcat]

Is anyone else using Great Value Concentrated (8.25% Hypochlorite) bleach? I had been using Stop&Shop for a couple of years with no problems, but switched to GV because I couldn't get the big bottles of SS. Ever since, my pH has been climbing. Prior to this, my pH was steady at 7.4 and would drop slightly after a heavy rain. It is now at 7.8 and my skin feels like a mild sunburn after getting out if I don't rinse off. I am using the Taylor R-0870, R-0871, R-003. My levels are:

FC = 0.0 (I know! Sorry!)
CC < 0.2
pH = 7.8
CYA = 45
TA = 110

[FormerBromineUser]

I don't think the change in bleach is the problem at all. I hope your pool survives the low FC!!!

[bottomcat]

I just added 110 oz of the S&S. It should be fine. Why do you suppose pH would rise? Woulld it make sense that at 7.8 it could burn skin?

[FormerBromineUser]

7.8 is at the top of the range. Maybe your skin is more sensitive. Maybe also the pH is actually higher than 7.8. The color matching is hard for some people. Did you go ahead and lower it?

[bottomcat]

No. I've never had to do it before. I do have some Muriatic Acid (20% Baume) and I also have some "pH Minus" from Target. Should I attempt to lower? If so, what is the best method?

Thanks.

[bottomcat]

Okay, sorry for the lazy question. I watched the youtube video linked here about adding MA and I added what I guessed to be around 15 oz. Now, how long should I wait before testing and letting bathers in the pool?

[bottomcat]

Well I waited about 2 hours and retested. pH was still around 7.7 so I did an acid demand test, which indicated that I needed between 9 oz and 1 pint of acid to get to 7.4. I'll test again in the morning.

[FormerBromineUser]

I had a long day at work. You can swim as long as your pH is between 7.2-7.8. I am glad it is for sure under 7.8 now. I sure hope this takes care of your "burning" issue!

[bottomcat]

Thanks FBU. I tested this morning and it is at 7.5. Water is really clear too. Thanks and have a great Sunday!

[swimdaddy]

Sounds like everything is under control but wanted to add a little to "stir the pot" if you will. Ben has talked a bit about some pools running at a natural pH of 8, and that actually being an easier to maintain pH AND more comfortable. My pH tends to run higher, 7.6-8 at times, and I really don't worry about it much. The pool is clean and comfortable and that's all that matters. I find my eyes feel better with then pH is closer to 8.

The problem is that you cannot know how high your pH actually is once it gets to 8 because the test only goes that high. I have though about getting a digital tester so I can test more accurately. Maybe someday.

[Anonymous [GDPR] European in the UK]

bottomcat, you could, if you like playing, add the acid to bring down the pH to 7 and then aerate the pool water with a shop vac or pointing the returns skyward etc raise the pH but this will have the effect of lowering your ALK.
Bicarbonate causes a buffering of the pH in water at around 8.4. Too high really isn't it (needed for tiled/plaster pools but not vinyl) so if you run like I do with a ALK level between 35-40ppm the pH is way more stable at 7.4.

The stoopid pool industry hasn't made a distinction between one type of pool and another. Then there are other pH buffers which are more acidic so could oppose the ALK level like the CYA stabiliser or adding a little magnesium chloride instead 100% of sodium chloride, (you could still add magnesium chloride to a chlorine dosed pool as well)