Ta Low And Ph High...please Help!

[torizoe]

First of all... thank you all for having such a great forum. I've been reading this section for a couple weeks getting ready for our spa. I thought I was ready. Ha!

We bought a used 2006 Sundance Optima. Performed the decontamination process. Did a fresh fill yesterday afternoon and then things started to go downhill.

3/7

Fresh fill:

Pulled water before completely filled:

CH 50

TA 50

pH 7.3 or .4

Went to spa store and had them test water. This water was after pumps were on and water heater on but water not heated:

CH 60

TA 50

pH 8+ ( she tested twice)

Came home and testest the extact same water (from same bottle I took to Spa store):

CH 60

TA 50

pH 7.5 (test twice)

Added 12 TBS of Calcium (according to directions)

Ran pumps for 30 minutes:

CH 150

TA 60

pH 8 or higher

Added 3 caps of Gentle Spa, according to bottle directions.

Waited about 15 – 20 minutes.

Added add’l 5 TBS of calcium.

Waited about 20 minutes:

CH 200 maybe 190

TA 60

pH 8 or higher

Added a capful (approx ½ oz according to label).

Waited about 20 minutes:

CH 200

TA 60

pH 8 or higher

Added 2.5 capfuls (approx 1 ¼ oz):

Was gone for 2 ½ hours:

CH 180 (maybe when I test at 200 I was going for a darker blue. 180 is a light blue but blue not purple)

TA 50

pH 7.7 or .8

At this point it is late and I can’t mess with it anymore. I don’t want to leave it without adding any sanitizer so I go ahead and insert N2 cartridge and add 3 tbs (little less) of dichlor. (Followed N2 directions for amounts – 1 ½ TBS for 250 gallons.)

3/8

7 am

CH 170

TA 60

pH

[torizoe]

Shoot..I posted without finishing.

Today is:

CH 170 or 180

TA 60

pH 8 or higher

Pool temp is up to 103. We won't usually have it that high but were hoping to use it this weekend. Silly me.

I'm really at a loss. I'm pretty sure I've made a ton of mistakes already and I just don't know where to go from here.

In addition, I think I added too much dichlor last night even though the N2 instructions called for it. Maybe I'm just not testing the FC right but it is still around 10ppm, I think.

I just can't figure out how to lower my pH without lowering my TA.

Any help would be GREATLY appreciated!!

~Lara

[torizoe]

One last update for now..

I don't think the spa is really 103. It just doesn't seem that hot. More likely around 100 or less.

I plan to use the N2 system with mps and dichlor as needed. At this point there is no mps in the spa.

The N2 directions call for a CH of 200-400. That is why I kept bumping it up. But using the pool calculator maybe I should have left it at 150.

Thoroughly confused on the best way to proceed.

Thanks again!

[chem geek]

Unless you keep your TA low, you don't want the CH to be high and the N2 directions are ridiculous for a spa. They aren't accounting for the higher temperature of the water and the greater risk of calcium carbonate scaling in the gas heater as a result. Leave the CH where you have it. Just start using the N2 with MPS and occasional Dichlor and see which way the pH goes. If it tends to go up, then lower the TA but not below 50 ppm. If it tends to go down, then raise the TA, but not much above 80 ppm if you have your CH at 200 ppm.

[torizoe]

Thank you so much for your reply!!

I've slowly been adding thio-trine neutralizer to get the FC down so we can actually use the spa this evening. I think we are almost there. Oddly enough, as I've gotten the FC down it looks like my pH has gone down to 7.8 again. Although it is dark now but I've looked at it in various rooms and I think it has gone down.

Last reading was:

FC 5.5

pH 7.8

TA 60

I'm not sure how I was doing it wrong but today my CH is coming out at 170ppm so that's good, right? Or at least better than 200. The spa store tested it at 140 which would be great but I can't get that number when I test and I've tried numerous times.

So I think at this point I'll stop worrying and use the spa tonight. We'll see what happens once we start using it and adding MPS.

Once again, thank you for your help. I'm sure I'll need it again!

Have a great evening!

[chem geek]

When the chlorine is very high (usually above 10 ppm FC), the pH can read artificially high since the high chlorine level can oxidize the dye in the pH test to a different chemical with a different color. The quote from Taylor's Pool & Spa Water Chemistry booklet on the issue of a high FC causing a false high pH reading is as follows:

FALSE READINGS: high levels of chlorine (usually > 10 ppm) will quickly and completely convert phenol red into another pH indicator (chlorphenol red). This new indicator is a dark purple when the water's pH is above 6.6. Unfortunately, some pool operators mistake the purple color for dark red and think the pool water is very alkaline and wrongly add acid to the pool.

When a sanitizer level is not extreme, only some of the phenol red may convert to chlorphenol red. However, purple + orange (for example, pH 7.4) = red. This error is more subtle as no purple color is observed and the operator does not suspect that a false high pH reading has been produced. Some operators neutralize the sanitizer first by adding a drop of chlorine neutralizer (i.e. sodium thiosulfate). However, thiosulfate solutions have a high pH and, if heavily used, may cause a false higher sample pH.

Also, when chlorine is used/consumed, this is generally an acidic process so the pH may drop.

Note that MPS is acidic so when you start using that (with Nature2) it should help keep the pH down.

[torizoe]

Thank you!

Used the spa for first time last night. Added MPS after soak as directed.

Levels this morning were (about 12 hours later):

CH 170 (I will likely stop testing this so often since it seems to be staying there)

pH 7.6

TA 50

So I guess I'm okay although I am worried about the TA dropping more since 50ppm is usually the lowest recommended on this site. But I guess I'll cross that bridge when I come to it.

Thanks you again for your help!!

[chem geek]

If you find the pH tending to drop, due to the use of MPS, then you can raise the TA level to compensate for that. TA is a source of rising pH especially with aeration so helps counteract the drop in pH from net acidic chemicals including MPS.

[orangedawg]

Okay, I thought I would tag along on this post as my TA is low, but ph high, instead of posting a new one, as I have a real issue with Low TA and high PH. I'm a newbie and have tried to set up my tub, but having issues. If I should post this in a new post. please let me know.

Okay, here's the info:

Jacuzzi j365 (lists 374 gallons as size, but I'm using 350 gal as the size on pool calculator, as I assume 374 is to the brim).

I have read it seems innumberable posts about getting the TA to get to it's balance point by aerating tub for 30 minutes to get ph to rise, add acid to lower TA and ph, recheck after 30 minutes, aerate to get ph down, etc. I'm using the Taylor 2006 kit, I think it is called. When I am aerating I'm am using all jets, air, and waterfall per nitro's guide.

Also, I have not added any chlorine/bromine/borates, etc. during this entire testing below.

So, I started with this:

CH 70

TA: 70

ph: 8.0+

I have not added any chlorine/bromine/borates, etc. during this entire testing.

So, reading what CH, TA, and ph should be, I started to increase CH and lower ph. Added a CH increaser and added dry acid to lower ph. Aerate for 30 minutes.

Next test:

CH 180 (overshot this a bit, but it came down, as you will see as tub warmed up, though not sure why it did so)

TA: 70

ph: 8.0+ (top end of ph scale using Taylor kit)

add 3 tsp dry acid, aerate 30 minutes

CH: 160

TA: 60-70 (hard to read exact change)

ph: still 8.0

more dry acid 3tsp, aearate

CH: 160

TA: 40

ph: 7.8-8.0

At this point, I added one drop of acid demand test in Taylor kit, and that one drop changed ph in test tube to 7.2

Still thinking I need to drop ph, as per nitro's instructions, the idea is to keep adding dry acid and aerating until ph stabilzes at desired level (7.6). So, 1 tsp dry acid and aerate:

CH: 150

TA: 40

ph: still at 8.0 or so, when add one drop in acid demand test, ph drops in test tube to 7.2.

To repeat, during this entire testing I have not added any chlorine, bromine, borates, etc. I am just trying to get water balanced prior to adding that (BTW, I will be using the 3 step bromine method).

According to pool calculator, to get desired results of CH at 150 and ph at 7.6, my TA should be at 70 to have saturation at -.03. However, that seems somewhat contrary to nitro's method of TA/ph balance.

I'm stumped as to what to do. I'm tempted to add baking soda to get TA back up to 70, which according to pool calculator is where it is supposed to be, but then ph will be high again.

Any help for this newbie?

[chem geek]

Every time you aerate, you are raising the pH. If you add the acid in the last step without aerating, you should be able to have the pH get lower where you want it. Of course, at that point if you want to lock in the pH more you can add 50 ppm Borates (say, from boric acid) which will slow down the rate of pH rise. When using hypochlorite sources of chlorine (bleach, mostly) you need both the TA to be low and to have an additional pH buffer such as 50 ppm Borates. The low pH by itself may slow down the rate of pH rise and certainly will lower the amount of acid needed to restore the pH, but to have the pH rise much more slowly you need the additional pH buffering.

Some people use a phosphate pH buffer, but that can get messy since it initially precipitates calcium phosphate.

[orangedawg]

Thanks! I was getting confused at always aerating when adding acid to get to the TA balance point. Should I raise my TA to 70, don't aerate, and then add dry acid to drop ph to 7.6-7.8? Pool calculator says I should be at TA of 70 with CH at 150 to get saturation at about 0. I do plan on adding borates (Gentle Spa), but it hasn't arrived yet (ordered I last week).

BTW, I will be using bromine using 3 step method. So, should I increase TA to 70 as suggested by pool calculator?

[chem geek]

Well, bromine tabs are normally acidic. Why don't you see what happen to the pH with normal use right now. If the pH tends to drop, then raise the TA; otherwise, leave it alone and just add the borates. The Pool Calculator is not set up for recommendations for spas, specifically not for the low TA that is usually needed unless using acidic disinfectants or oxidizers.

[orangedawg]

Okay, here's my latest readings, after putting in bromine bank and using 7 oz. of 6% bleach to shock in 350 gallon hot tub 12 hours ago:

TA: 50

CH: 150

Bromine 6-7, kind of hard to tell.

PH: 7.8-8.0, again hard to tell for me.

I added one drop of acid demand test in my Taylor kit and it then ph read 7.4.

So, is the 7.8 okay? I have not put in my bromine floater yet. I plan to add Gentle Spa bromates. Should I try to drop ph by adding 1 tsp of acid before I add bromates?

Does the number of drops correlate to a level of dropped ph? Like, is 1 drop = to .2 of ph? In my test above, since I had a hard time telling if ph was 8 or 7.8, does the one drop of AD mean .4 in ph level?

[chem geek]

I'd lower the pH to 7.4 or so, maybe lower, if you are going to use Gentle Spa because people have reported that it raises the pH and you'll probably have to add more acid after you add this product. Unfortunately, it's not as neutral as pure boric acid which is only slightly acidic.

The number of drops correlates to the quantity of acid (or base, if doing the base demand test) you need to add. The Taylor book that comes with the test kit has charts in the back, though they are set up for pools but you can scale accordingly. As you are seeing, one drop moves the pH a lot and that's because your TA level is low. That will change after you've added the borates.

[brianthepoolman]

if you are fighting to get your PH low and keep it low, it could be due to your spa being equipped with ozone. ozone regulates PH to a high level, you can adjust it for a day but in the end it will climb right back up

[orangedawg]

First, thanks to all who have helped!

Okay, here's where I am now:

PH: 7.8 (could be slightly lower, maybe 7.7, hard to read color on Talyor test tube)

TA: 50

CH: 150

Temp: 100

Bromine: 5

I added Gentle Spa about 20 hours ago.

As others have noted, after I added Gentle Spa bromates (powder formula, added 1 1/4 cups, directions said 1/2 cup per 150 gallons, my tub is about 350 gallons (Jacuzzi J 365), the PH went way high, well over 8. So, I slowly added dry acid, a bit at a time, to get it where it is now. The values I have listed above have been steady for about 12 hours (using bromine floater).

Should I leave values where they are now, or add another 1 tsp dry acid to drop ph down a notch (dry acid test, 1 drop, drops ph to about 7.6 in test tube)?

Also, this is a used tub (just got it, but did the spa flush and decontamination), and it has a Balboa UV ozonator, but I'm not sure it is working as I don't know how old ozone is.

[brianthepoolman]

there are 2 types of ozone, corona discharge and UV light. one has a light bulb and one don't. The more you mess with the TA the more the PH with bounce. I tell all my customers who have ozone to worry about the TA more than the PH. Your TA should be around 80 to 100. Bromine level is way to high. the lower the TA the more effective bromine is. If you were my customer I would recomend that you leave the tub go for about 5 to seven days then get a reading on your test results.

[orangedawg]

Thanks! I thought bromine was supposed to be between 4 and 6 according to "bromine for beginners". And I am not sure if ozonator is producing ozone as it is a used tub and not sure how old the Balboa UV ozonator is.

[brianthepoolman]

Balboa makes both types of ozone but mainly the sell the corona discharge, the ozonator should have a little blue light somewhere on the vessel, depending on age of tub it should still be working, most last for several thousand hours. Bromine levels should be between 1PPM to 3PPM.

[orangedawg]

It's called a Balboa 59024 O3zone UV Electronic Ballast Ozone Generator. It is "cylinder shaped" maybe a foot long. I don't know how old it is. I plan on getting a test kit to see if the thing is even producing ozone, unless there is another way to test it?

[brianthepoolman]

that model is Ultra violet light bulb so on the end it should have a blue light glowing, if it doesn't then its either bad or not plugged in or wired in. Ozone has the smell like after a lighting storm, just a fresh smell to it. I usually try to smell the bubbles coming up from the water, where the ozone jet is. Hope this helps ya.

[orangedawg]

Thanks! I will check out to see if my bulb is glowing.

And I just checked the water:

ph 7.7-7.8 (I drop of acid demand drops to 7.5-7.6)

TA: 50-60 (probably in between, it's a pale pink/red at 50, next drop turns it a true red)

CH: 150

Bromine: 5

Borates: I don't have a test for this, but as noted above, yesterday I put in 1 1/4 cups of Gentle Spa (directions say 1/2 cup per 150 gallons, and I have a J365, so I'm guessing I'm 350 gallons or so)

I have the floater set pretty low and it has held these values above for 12 hours or so.

[Specks]

Hope you don't mind if I piggy back this thread also.

Setup:

in.clear bromine generator

APG ozone generator (corona discharge)

Testing with Taylor K-2106 FAS-DPD Bromine Complete Test Kit.

Bromine - 2.5

CH - 130

TA - 70

PH - 8.0+

In reading around the forum I see that ozone can cause the ph to rise. The in.clear system recommends 100-120 ppm on the TA. If I raise my TA to that level I'm afraid the ph will be out of control.

I also read Nitro's post on lowering TA until the ph is stable but then my TA will be much lower than the recommended level so I am sorta at in impasse on what to do next. If you have an ozone generator do you just deal with high levels of ph and keep the TA in range or?

Any advice would be greatly appreciated.

[Specks]

Ok so I now realize raising TA up w/ sodium bicarbonate isn't directly proportional to lowering the ph w/ acid. I got my TA back around 100 and the ph is about 7.8.

if you are fighting to get your PH low and keep it low, it could be due to your spa being equipped with ozone. ozone regulates PH to a high level, you can adjust it for a day but in the end it will climb right back up

So are you saying by using ozone keeping the ph in check is a losing battle? Because I have noticed I can lower it but like you said by the end of the day it's back around 8.0+.

[chem geek]

Ozone is injected into air and it's the aeration of the water that drives carbon dioxide out faster and that causes the pH to rise. A lower TA has less carbon dioxide in the water so it outgasses more slowly (and there are technical reasons why this lower rate is as the square of the TA, not linear). Also, the bromine generator generates hydrogen gas at one of its plates and that also aerates the water. If you lower the TA significantly (as low as 50 ppm, if necessary) and use an alternate pH buffer such as 50 ppm borates (usually from adding boric acid), then the pH can be more stable.

If you have an acrylic spa, then there is no calcium carbonate to protect, such as in plaster, so there is no need for a higher TA level nor for Calcium Hardness (CH). You do need pH buffering, but as I noted you can do that using borates that will not outgas carbon dioxide. TA is a SOURCE of rising pH in its own right. Also note that borates are a strong pH buffer against rising pH so will help prevent any scaling in the bromine generator, even if you did have calcium in the water (say, from hard fill water).