Cannot raise pH or Alkalinity

[dfmcapecod]

I've been through pool school and used the pool calculator and cannot seem to make any progress raising either pH or TA to acceptable levels. I have had no issues keeping Chlorine in check this season using the trichlor pucks in the skimmer baskets and shocking with liquid bleach on a weekly basis.

Having read the forum a few times, I'm thinking I need to stop using the pucks and switch entirely to liquid, as the pucks will keep pH down.

Last night I added 15 lbs of sodium bi-carbonate and still tonight (24 hours later) my pH is not registering on the test kit low value of 6.8 nor is TA testing showing any "blue" tinge to the water to actually validate TA accurately.

I have two test kits (both OTO for the chlorine) and the results are identical for the pH test which makes me believe that's correct. I only have one test kit to validate TA and it's one year old. When testing TA, even though I didn't start with a blue tinge water, I added 10-20 drops to "see" if I could get it to go a bit yellow and it still, at least to my eye was clear...

I would say the pH reading is getting 'closer' to 6.8 on the scale, but cannot be certain since I don't have any values lower to compare.

My question is, do I keep adding baking soda to this pool or am I doing something entirely wrong here?

Yes, it appears as if I have to invest in a better test kit, but I figure 2 different kits giving me the identical signals is saying I have something wrong.

TA - cannot validate accurately, extremely low.
FC - 1.0
CC - 1.5
TC - (adding FC and CC) 2.5? (OTO test)
CH - not tested.
CYA - not tested.

Appreciate the help here while I get a better test kit and some more confidence in what I'm doing.

Nobody is complaining of red eyes, burning eyes, and the water has been relatively clear until just recently now appearing a tad cloudy, but didn't want to shock again until I know what to finish doing with pH.

Thanks!
dfmcapecod

 

[beaumatt]

First off, I am no expert, but I have been using the BBB method for over a month now with complete success. In reading your post it seems like you are using the wrong thing to try and bring up your PH. You should be using Borax to raise your PH. The sodium bicarbonate (baking soda) should raise your TA, but depending on the size of your pool (10,000 gal) 15 pounds does not seem like much if your PH is that low. I just had to raise my TA and it took 24 pounds to get there. Once you get it set, it seems pretty stable (in my experience). To raise my PH (21000 gal) took two full boxes of 20 Mule Team Borax. I am a little confused about your TA test because all the ones I have used are green, not blue and there is no 'tinge' to it, they are completely green and change to red. It seems after adding the sodium bicarbonate you have added would at least be being reflectd in your TA number.

Someone much more expert in this process should be along, but this may give you an idea or two on something to review in the pool school section.

Good Luck!

 

[JasonLion]

15 lbs of sodium bicarbonate in 10,000 gallons should have raised the TA by over 100, which should be very obvious on the test. Some of the less expensive test kits include a TA test that can bleach out at medium and high FC levels, and it is fairly easy to read a fairly high FC level as "something above 2" using an OTO test, so that seems like the most likely possibility. It is also possible the TA test has gone bad.

Most likely the PH tests are correct, and the PH is still very low. But the TA must be somewhere well above zero. I would switch to adding borax (or soda ash if that is all you have) until you get the PH in range. By then either the TA test will start working again, or you need to get a new TA test.

 

[dfmcapecod]

15 lbs of sodium bicarbonate in 10,000 gallons should have raised the TA by over 100, which should be very obvious on the test. Some of the less expensive test kits include a TA test that can bleach out at medium and high FC levels, and it is fairly easy to read a fairly high FC level as "something above 2" using an OTO test, so that seems like the most likely possibility. It is also possible the TA test has gone bad.

Most likely the PH tests are correct, and the PH is still very low. But the TA must be somewhere well above zero. I would switch to adding borax (or soda ash if that is all you have) until you get the PH in range. By then either the TA test will start working again, or you need to get a new TA test.

Thanks!

Yes, using the pool calculator that's where I derived the 15lbs baking soda add, and it's what was in my inventory at the time. (No Borax yet).

As for the FC level, I'm 99% sure it's < 2, as two different OTO test kits gave me this result and I'm adding the neutralizer for the TA test as well. Therefore I'm going to have to assume the TA test is bad, would this be possible if the test was left outside in a shed for a winter? I'm not sure that it was, but it's a good possibility.

I've ordered the 'Taylor Complete FAS-DPD Test Kit - Chlorine K-2006' kit and should have that in a few days, until then, I'm going to add some Borax tomorrow.

How long after adding Borax or Baking Soda do I have to wait to A) test for pH/TA and B) before you can go in the pool?

Will post results later.

-dfmcapecod

 

[PaulR]

Cape Cod, cool! When I was a kid we used to go to a campground in Truro for a week every summer.

I can't say specifically but I would guess that exposing test reagents to excessive heat or cold will shorten their lifetimes.

Usually we say give the chems half an hour with the pump on to mix properly. Then you should retest pH and see how you're doing.
--paulr

 

[chem geek]

If the TA test turns red immediately, then the pH is below 4.5 so it's even technically possible for the TA to be negative (which just shows as 0 in the test since it turns red right away).

Since both the pH and TA are presumably extremely low, using pH Up (or Arm & Hammer Super Washing Soda) should raise both. Just don't add so much as to raise the TA too high. As was noted in an earlier post, using 20 Mule Team Borax will raise the pH with less of a rise in TA.

Of course, if you question your TA test, then you could replace those reagents.

 

[dfmcapecod]

Progress.

This morning I added another 5lbs of baking soda. Now the pH is normal. I presume, but do not know for sure that my TA is now quite high because I don't know for sure that my test is working correctly. (waiting for a new one).

When I use the TA test, the water has a blue 'tinge' but is certainly not really 'blue'.
It's definitely NOT going red.

This morning, I also added 60 oz of 10% bleach to raise FC up to 5 from .6.

Full day (12 hours) of 90 degree sun and the FC is back down to around 1.6.

Also, the main drains, the steps, and skimmers now have a slight brown tinge to them underwater, this has happened before and gone away but I was never able to identify *why*.

Another observation is that now having added about 20lbs of baking soda, the buoyancy of the pool seems noticeably increased. I believe this has to be from salt in the baking soda????

So my open questions are:

1) the brown tinge doesn't seem to represent algae or anything else I can find on the forums or google images so what is it?
2) does that sound about right for FC loss during a clear 90 degree day?
3) wanting to move completely to a BBB method, I've stopped using trichlor and convert entirely to liquid bleach. Because I'm doing this, which should stop slamming my pH and TA low, what's the right amount to shock the pool without knowing my CYA levels? (I'm still waiting for the test kit that has the CYA test to arrive via mail).

Thanks for everyone's help!

-dfmcapecod

 

[PaulR]

For the brown tinge: Go to your medicine cabinet, pull out the Vitamin C tablets, and drop one on the brown stuff. If it goes away, it's iron. If not, somebody else will have to suggest something.

For the FC loss: Because we don't have a clue about your CYA, we don't have a clue whether the loss is reasonable. If your CYA is way low, you can certainly lose a lot of FC every day. But, you shouldn't lose any overnight; if you do, then you have algae or something. If overnight the FC is steady, then it's probably just low CYA.
--paulr

 

[Ohm_Boy]

How's your circulation? Well, I mean the pool's circulation. How long are you running your filter? And is there a pool store nearby? If so, it might be interesting to take them a water sample to test. When they tell you what all you need to buy to fix it, just thank them and tell them you'll be back.

 

[dfmcapecod]

1 HP pump, I run it about 16 hours a day, @ 8-14 PSI reading on the Hayward DE filter, 10K gallon pool, clean skimmers daily, clean filter basket weekly. I've been backwashing when the pressure gets up around 15-17, it will drop back to 8-10.

-dfmcapecod