TA at 0 and PH very low - Which should I tackle first?

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bjbarlowe

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May 9, 2016
54
Lynchburg, VA
I hope I've not been posting too much but you folks here have been super helpful. I've learned from Pool School that raising TA will also raise the PH. Right now my TA is at 0 and my PH is very low (test results below). To get TA up to 60 ppm, Pool Math says to put in 11 pounds of baking soda. I'm planning on doing that in a few steps, testing PH and TA in between as the Pool School suggests. However, I'm looking for the best strategy to do this - should I deal with PH or TA first?

The reason I'm asking is because in Pool Math, it says I need a lot more borax to raise the PH once my TA is up to 60 ppm (19 oz if TA is 0 and 99 oz if TA is 60). Why does that make a difference? Is it simply that TA buffers against changes in PH so it takes much more to change it if TA is higher? Given that, would it be better to raise PH first and then deal with raising TA?

If I do add baking soda to raise the TA first, how much can I expect this much baking soda to to affect my PH? I'm hoping it will raise it to normal levels, but I have borax on hand to finish the job if it doesn't.

After adding borax and baking soda, how long should I filter the water before testing?


Latest Test Results:

FC = 0
PH = <6.8, my test was light yellow. It's likely lower than that.
TA = 0
CH = 110 ppm
CYA = 80 ppm - Working on lowering that now by replacing half the water. Got some good advice in another post on this.

For the record, I'm working on opening a pool for the first time that's not been well-maintained in the past.


UPDATE 5/11:

Thank you all for your help. I just finished replacing water to bring my CYA level down and I retested as you all suggested. I found that my PH and TA did not change. Test results below:

CYA = 40 ppm
PH = <6.8 - probably much lower
TA = 0 ppm
CH = 110 ppm

I'll be adding baking soda to raise TA. Pool Math says to add 11 pounds to get it up to 60 ppm. I'll add half that now, test and then add more. Hopefully that will bring the PH up some too and then I'll add borax to bring that up the rest of the way.


UPDATE 5/11:

I added Baking Soda which raised my TA to 70 ppm. PH is now readable and is at around 7.0 (probably more like 6.9). Pool Math says to add 80 oz by weight of borax to raise the PH to 7.6. I will try to do that tonight or tomorrow and retest. My main concern is that borax will raise my TA by about 12 ppm, which I know isn't the end of the world, but I was hoping to keep it a bit lower.

I realize now I misunderstood some of your advice and I should have used less baking soda to get the TA to around 50 or 60 ppm and then go the rest of the way for PH with borax, but I guess you just live and learn. I understand if the PH drifts up due to the high TA, Muriatic Acid will lower PH and TA as well, so I suppose it's not a big deal.

I don't think I mentioned above either that my pool currently has algae in it, which is why I'm trying to get the water balanced so I can SLAM it. I've heard that getting rid of the algae may also raise PH. Is that true?

Please let me know if you see any red flags with this plan. Thanks!


UPDATE 5/13 -

After adding borax, TA is up to around 80 ppm, but PH is at 7.2 and I'm ready to SLAM. Spent the evening brushing and vacuuming algae and I'll be adding my initial shock tonight. Thank you all for your help and I'll know in future to be a little more careful with the baking soda.

UPDATE 5/15 -

My SLAM has gone surprisingly well. I think I was able to vacuum most of my algae out to waste and the rest was taken care of within the first night and day after adding shock. I passed a OCLT test last night, my CC is at or near 0, and the water is quite clear. Thank you all so much for your advice and encouragement. I'm so glad to have found such kind people on this great forum!

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When your TA is zero your pH is likely below 5. Dump all 11 lbs in and give it a few hours/overnight to mix. When you retest you should get a TA result and might even have a readable pH. From there you can fine tune your pH and TA.

From my HTC One via Tapatalk
 
Thanks! I'll do that and give you all an update.

- - - Updated - - -

Marian, good point. Yes, I'm sure it will be different. I've drained and refilled all day yesterday but had to pause overnight. Now it's refilling again and should be done in a couple hours. I think I'll let the water filter for awhile to be sure the old and new water is mixed and retest before adding any baking soda.

Thank you both for your help.
 
The PoolMath calculator has a function at the bottom "effects of adding chemicals". Give that a try.

Enter the amount of Baking Soda you want to add, see what effect that has on the TA and PH. So say the TA will go up to 60 and he PH will rise .13. Add with the current test numbers, and put the result in the "now" column and recalculate dosages. I do this often when I come across your situation. You can also look for soda ash "Arm and Hammer Washing Soda) in the laundry aisle, this raises both pretty well....
 
As frustratedpoolmom said you can use Pool Math to calculate the effects of adding things to your pool. Once you plug in your pool volume there is a calculator at the bottom to show the effects of adding different things to the water. In this example I was looking for the effects of a 3” TriChlor tab on a 14,000 gallon pool.(note: 3" TriChlor pucks are usually 8oz)

It looks like this:

View attachment 47846


You can select almost anything TFP would normally advise to use in your pool to see what effect it will have on your water.
 
PoolMath is not entirely accurate when your TA is zero and your pH has bottomed out. Here is one explanation supporting why I always recommend only messing with baking soda at first when dealing with a situation like this. Emphasis added.

chem geek said:
If you use baking soda in water with very low pH, it significantly outgasses carbon dioxide and that's how the pH gets raised by converting bicarbonate to carbon dioxide. You can't overshoot the pH that way, but you can overshoot the TA.

With pH Up, you can overshoot the pH though it's less likely to overshoot the TA.

As an extreme example, if I start with a pH of 4.0 (with a -4.4 TA) and have an over-carbonation ratio of 10:1 so that most of the carbonates got outgassed, then adding 11-1/4 cups of pH Up (sodium carbonate) per 10,000 gallons would get to a pH of 7.5 and TA of 68 ppm if there were no carbon dioxide outgassing. If there were outgassing, then it would take less product to get to that pH, but the TA would be lower.

If I add bicarbonate instead, then it would take 19 cups per 10,000 gallons to get to a TA of 80 ppm, but without carbon dioxide outgassing the pH would be 6.65. If there were not enough outgassing, then one could aerate to raise the pH more. If one used bicarbonate alone to raise the pH to 7.5 then if there were no outgassing it would take 180 cups of bicarbonate and the TA would be over 800 ppm -- of course that doesn't happen because outgassing would occur at higher TA levels.

So the bottom line is that one has to be careful not to overshoot the pH with pH Up and not to overshoot the TA with bicarbonate. At least with bicarbonate it is known how much it increases TA and furthermore that amount is independent of the amount of outgassing. I would just caution that if one uses bicarbonate that one targets the TA and if the pH isn't high enough then stop short of the target TA and use pH Up to top off (or Borax if one prefers).

Arm & Hammer Super Washing Soda is around $5 for 55 ounces so 11-1/4 cups would be 103 ounces weight so about $9. Arm & Hammer Baking Soda is around $2.24 for 4 pounds so 19 cups would be 190 ounces so about $7. So using the baking soda looks like it would be less expensive.

Note that this absolutely positively is not the way to raise the pH if it's already in the measurable range (i.e. > 6.8). This would only be done when the TA is initially red so <= 0.
Click to expand...
 
Here's an update. I added Baking Soda which raised my TA to 70 ppm. PH is now readable and is at around 7.0 (probably more like 6.9). Pool Math says to add 80 oz by weight of borax to raise the PH to 7.6. I will try to do that tonight or tomorrow and retest. My main concern is that borax will raise my TA by about 12 ppm, which I know isn't the end of the world, but I was hoping to keep it a bit lower.

I realize now I misunderstood some of your advice and I should have used less baking soda to get the TA to around 50 or 60 ppm and then go the rest of the way for PH with borax, but I guess you just live and learn. I understand if the PH drifts up due to the high TA, Muriatic Acid will lower PH and TA as well, so I suppose it's not a big deal.

I don't think I mentioned above either that my pool currently has algae in it, which is why I'm trying to get the water balanced so I can SLAM it. I've heard that getting rid of the algae may also raise PH. Is that true?

Please let me know if you see any red flags with this plan. Thanks!
 
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Bummer. I was afraid of that baking soda, but oh well. You want to get your pH ONLY to 7.2 (not 7.6), for the slam so just add enough borax to get you there. Once you get to 7.2, slam away and don't worry about those other numbers for now. Getting rid of algae won't affect your pH that much. It's just that TFP doesn't advise testing pH during a slam as you will get FALSE high readings.
 

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UPDATE 5/13 -

After adding borax, TA is up to around 80 ppm, but PH is at 7.2 and I'm ready to SLAM. Spent the evening brushing and vacuuming algae and I'll be adding my initial shock tonight. I'm using cal hypo (unstabilized) since I had some on hand from the previous owner and my CH level is only at 110ppm, but it will be bleach and liquid chlorine from here on out. Thank you all for your help and I'll know in future to be a little more careful with the baking soda.
 
Kiki
bjbarlowe said:
UPDATE 5/13 -

After adding borax, TA is up to around 80 ppm, but PH is at 7.2 and I'm ready to SLAM. Spent the evening brushing and vacuuming algae and I'll be adding my initial shock tonight. I'm using cal hypo (unstabilized) since I had some on hand from the previous owner and my CH level is only at 110ppm, but it will be bleach and liquid chlorine from here on out. Thank you all for your help and I'll know in future to be a little more careful with the baking soda.
Click to expand...
just from this update I can tell you are catching on. Low on CH and need to start the SLAM, use calhypo that you have on hand.


It's all a learning process. Every one of us here started where you are - good luck with the SLAM.
 
Thanks all. The SLAM is going great! I put the chlorine into a minty green pool last night and woke up to a pretty blue pool this morning. The FC levels are still quite high. Higher than I expected at 19 ppm. I only meant to put in 17 ppm of chlorine, but I think my pool volume calculation was a bit off.

Maybe there wasn't so much algae as I thought also. I think I got a lot of it out with vacuuming to waste. I didn't do a CC chlorine test because time was limited, but I did smell that chlorine smell, so I imagine its in there. I'll do a CC chlorine test too this afternoon so I can get a better idea of how much the FC is working.

Thanks, all!
 
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