Accidentally lowered ph too much -- do I need to fix or can I wait?

TA is low but don’t know the value. Pool store had me add a bunch of bicarbonate last fall. I’ll drop off a bottle for testing tomorrow if 6.6 is ok for a day or two.

Bperry said:

Test it with your own test kit and report back. Cleaning the cell with acid reduces its life. Dont do that unless you see visible scaling.

Dont listen to anything the pool store says to do.

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Thanks all! Just got back home. Turns out that my test kit includes the reagents for total alkalinity. I got 50ppm and the test kit says to aim for 80-120. That also agrees with the test strips I normally use.

I also re-tested pH. The liquid test kit bottoms out at a pH of 6.8 and the yellow color pretty much matched 6.8. My pH meter says 6.6 though.

Pool is supposedly 26,000 gallons. So what does this all say I should do about the low pH? Is Sodium Bicarbonate (baking soda) the right thing to add? I'm sure the pool store has something expensive to sell me. Sam's Club sells baking soda for far less than Leslies does, and I'll bet Lowes has it as well (never looked). Will that boost the pH?

That said, I've gotten somewhat complacent because the chlorine generator works perfectly, keeps the chlorine level between 3 and 5 running at 40% output and I only have to add a quart or so of acid every 7-14 days as the pH climbs past 8.2 and I shoot for 7.4 or so. I also have not had algae problems in years. Water temp is 76 right now and was crystal clear until Tuesday's storm blew a bunch of leaves and pollen into the pool. Other than acid, I also add salt after I backwash a few times: I have a digital salt meter like the pH meter. Right now, the meter reports 2600ppm and that has always wildly disagreed with the 3200ppm that the flow sensor reports. So I try to keep the salt level between the two values: add a bag when my meter drops to 2600, and that bumps the flow sensor reading to 3400, still in range. Pool store is useless when it comes to measuring the salt level (and apparently useless for everything else as well).

Regarding cleaning the Aquapure PLC-1400 chlorine generator: it's 4 years old and this is the second time I've cleaned it -- I use 4 parts water, 1 part 32% muriatic acid but it's kind of a lot because I use what used to be a kitty litter plastic bin, fill it mostly with pool water, add the acid and make sure that the water level doesn't get to the electrodes. Someone really needs to make a plug for the chlorine generator holes so I can just fill it up but I've never been able to find one for a reasonable price.

I noticed the chlorine level was very low after the rainstorm (pool level rose by about 2" and then I took advantage of that to backwash) and I had a note to clean the generator this spring. It did have visible hunks/deposits and I was not able to dislodge them with chopsticks (my usual procedure) or a high pressure hose. The diluted acid bath took about 30 minutes but the deposits weren't completely gone even after that time. I wonder if a powerwasher is a good idea?

Regarding the pool store, I only take a bottle in about once a year to get a data point. It usually doesn't match the testing that I do, but I have not tested for TA before, and they test for hardness (1000ppm) and phosphate (typically 1000ppm).

Thanks!

Thanks! I installed and subscribed to the app. No idea it existed.

Last question: I’m going to raise the TA as you suggested to help prevent scaling but do I need to get the pH in range with the borax or can I wait just a couple of weeks for the pH to rise by itself as it normally does? We aren’t swimming yet. Or is 6.6 just too low to let it go?

17 lbs of borax (Sodium Borate?) or 8 lbs of soda ash (Sodium Carbonate) sounds like a lot to compensate for maybe an extra quart of unneeded muriatic acid in the pool. Is there any downside to adjusting the ph in this way?

Thanks again!

AUSpool said:

Below 7.0 is to low but that 6.6 is from your meter and if it’s never been cleaned, calibrated and stored properly it’s not worth a cracker. Default to your drop test which was 6.8 but is probably back to 7.0 by now and still rising. Let it sit.

There is no need to go down to 7.4. Try 7.6 as a new target. You’ll use less acid and your just a little further away from dipping below 7.0.

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Thanks! I'll monitor the pH over the next few days and then bump the TA. Sounds like a plan.

proavia said:

What exact test kit are you using?
How old are the reagents?

Test strips are as worthless as pool store testing. Toss them in the trash.

Suggest you review/reread Pool Care Basics and explore the extended test kit instructions

Extended Test Kit Directions Archives

www.troublefreepool.com

Consistent, scheduled testing and dosing using one of the recommended test kits will keep you pool sanitary and trouble free.

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Test kit is from Style Pool Products, maybe a year old. Not sure where I bought it, but probably Lowes, which is also where I get acid and salt (when Sam's Club isn't clearing out salt at the end of the season -- always a fantastic deal). I use test strips mostly as a quick check of chlorine in the pool and follow up with reagents if it's not as I expected. pH testing is almost always with my meter which seems to match the reagent test. Of course, it's only checking the top inch or two of the water because I can't dunk it but I measure away from inlets.

Yesterday morning I added 4 lbs of pure baking soda, from the grocery store Just tested and now I'm at 60ppm TA. pH has risen to 7.1-7.2 according to my tester and confirmed with the reagent test kit.

Yesterday morning, the water was again crystal clear. I appear to have recovered from my "too much acid" mistake, and chlorine levels are at about 5 with 70% production so I'll keep an eye on that.

Thanks!

proavia said:

You may want to recheck your test results in your PoolMath logs
CC of 7.0 isn't a good thing. I'm guessing you meant FC of 7.0 - which means you are still missing the CC result.

Again, test strips are worthless. Don't trust them.
I'm unable to find anything specific on the internet about your Style Pool Products test kit.
List the test it does and the reagent numbers.

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My test kit is "Pool Style" (see link). The word "Pool" in the logo is printed in light ink and had faded so I thought it was just "Style". The kit I have is 5-way: chlorine/bromine, pH, acid demand, and total alkalinity. I use test strips for cyanuric acid and free chlorine (mostly to make sure there is some). CYA is 40 according to the test strips -- I like to keep it low because I've heard CYA is a carcinogen and I rarely use pucks so it doesn't get replenished that way. I do have some on hand that I can add.

The combined chlorine is down to 3-5 (that's the liquid test range; test strip says 5). I updated that in PoolMath now, and I'm thinking it was high because I still had the pool floater dispensing pucks but I took that out several days ago. Going to watch that to make sure the SWG is working properly again after debridement. TA is still 60 and pH is now 7.3, so going up .2 every day So I think I'm good there. Oddly enough, there is now some green algae on the side of the pool under the skimmer that I had to brush in (this might happen more often and the Dolphin pool robot gets it). I have a bottle of phosFree left over from a year or two ago, so I will probably use that up unless the entire process is a bad idea. Live Oak leaves and droppings are finally done falling into the pool, and as I said, the water is again crystal-clear.

I'll invest in a better test kit (do you have a link), but I don't want to pay a bunch as I don't test very often and the chemicals just expire.

Thanks!