Newbie needs help to stop the TA/pH madness

[Trailanimal]

2-weeks into bringing up a new spa. Used the dichlor/bleach method (350 gallons).

CH ~125
FAC ~ 3-5ppm...monitoring to keep over 2ppm (TC = FAC)
CYA ~ 20-25...yeah, a bit low, waiting for a Taylor K-1005 kit, bought the K-1004 initially?

So, here's the issue. I have very high alkalinity (TA ~ 240ppm) water (well) with a water softener. I had to add 1-cup of calcium hardener to get over 100ppm. I had to add over a bottle of dry-acid to get pH down to 7.5 giving me a TA of 50ppm. Unfortunately, even with little use, the pH drifts up to 8+ almost daily and requires 2 Table-spoons of dry acid to get it back down to 7.5. This eventually dropped my TA below 30ppm. When I tried to use baking soda to get it back to 50ppm (~ 2 Tablespoons), my pH went from 7.5 to 8.0??? Is there a trick I haven't read yet to managing water that has a higher relative pH to TA?

Should also note that FAC drops 2-3ppm overnight, not sure if this is normal or due to either lower CYA or the ozonator. I've only used spa a few times since "balancing" water and I have to add ~2ppm of FAC after a 30-45min soak. Is the 2-5ppm of daily added bleach (depending on use) compounding the issue as well?

Update : I had been waiting to consider borates until I had a good handle on water balance, but after reading more about it, I went ahead and ordered granular boric acid to use. Looks like this may be the best solution for my issue? Question here...do I adjust pH back down to 7.5 or lower, no matter the TA level and then add 50ppm of boric acid? After allowing to settle, would I then increase TA to above 50ppm and expect pH to have not changed appreciably?

Thanks in advance for any advice.

 

[JoeSelf]

1. Did you purge your new spa? Ahhsome is what most of us use.

2. Can you turn of the air to the jets. If so, do it. Aeration raises PH.

3. Ozone only or UV also. I lose about 1.5 FC overnight with UV and ozone running 8 hrs overnight.

Hold off on the borates until you get the PH/TA stable. It will be harder to make changes after the borates are added.

Can you share your poolmath logs?

 

[Mdragger88]

Use a light hand with baking soda. You can always add more later.
A little goes a long way in a small tub.
No need to chase the “perfect” ph.
Aiming for High 7’s (7.8/7.9) is fine. Letting it ride at 8.0 for a day or two is ok too.
Smaller drops also won’t effect the ta as harshly.
Add the boric acid once ta is 50/60.
Note that it is acidic so factor that in.
Once borates are in the picture more acid is required for the same results so be sure to include them in your poolmath calculations.

Consider switching to muriatic acid- dry acid contains sulfates which are bad for your heater.

As Joe mentioned adjust your jets so they aren’t aerating as much during standby.
Also make sure your water level is adequate (covering the jets) so less turbulence occurs during standby.

Adding bleach is no problem & doesn’t effect ph/ta.
Dichlor, however, is acidic so factor that in.
Poolmath effects of adding will show you its effects on ph & cya.

 

[Trailanimal]

Thanks for all the info!

I did drain and refill the tub the first week after installed by retailer. For many reasons that I won't go into here, including being set up for @ease use, the water chemistry got way off. My knowing next to nothing and the install team being very confused between traditional operation and using @ease. They gave me conflicting info and a bucket of chemicals! Once I did some research and got a handle on things, I removed the inline @ease system and drained the tub. I didn't know about Ahhsome at the time, but the water coming out of the drain hose looked clear (realize many things aren't visible). While filling with the hose in the filter tube, once the water got over all the jets, I again opened the drain to both push any air out and cycle more "pressured" water through the system. As I mentioned in my previous thread, my house water is very good quality, it comes from a deep well in a mountainous rural area and I have a two-stage silt-filter set-up before a water softener.

I only have an ozone setup, no UV. I don't have any dosing/measurement logs, just been using the manual calculator (no-app), wasn't expecting it to be so involved as to need an Excel spreadsheet! I will consider muriatic acid in the future, especially for the initial TA balance, given how how high TA is to start...again, was unaware of the side-effects of using dry-acid initially. It's amazing how much I've learned in just over a week using this forum and associated material. Too bad I didn't go through this site as a primer initially. I'm also amazed at how little the sales/service people I worked with knew and the company has been in the pool/spa business over 50 years.

I have read about the aerating effect on pH, but was a bit confused about just closing all the air controls for the jets. What about the heater and filter cycles, aren't they more efficient with jets being on? Also, I will still need the jets for adding chemicals using a "clean" cycle...correct? (2-pumps, but only pump-1 runs on high during "clean")

At the moment, it appears my water's preferential state is for TA = 40 +/- with pH ~ 8.0 (>7.8 & < 8.2). TA is essentially a buffer against pH dropping, so if my pH tends to drift higher only, is there a real downside to TA around 30ppm, if that's where pH ~7.5 is happy? Also, once I add borates which buffer against pH increasing, I may be able to increase TA a bit and still maintain optimum pH?

Final question related to dry-acid and sulfates. I really don't want to have to drain the tub again, especially since it took so long to get where I am. How at risk am I with the heater, given the amount of dry-acid initially used to bring down TA/pH? If after using muriatic acid for initial setup, small corrections with dry-acid should be okay...correct?

Thanks again!

 

[Mdragger88]

Use up the dry acid you have then buy Muriatic acid next time. We’re talking in the grand scheme of longevity here - not a one time instant damage situation. I imagine you’ll be out of the dry stuff by the next water exchange anyway.
As for TA - 40 is as low as you want to go. The ph can get unstable if you go lower.
The borates should help with rate of ph rise.
Not sure about your particular set up but my jets run fine without the air open- this doesn’t effect the equipment negatively. I only run my jets with the air open when I am using the tub not during standby.

Using poolmath is much easier than doing all the toilet paper math on the packages & the acid demand test and all that lol. Using the app is free, but a subscription($8/yr) is needed to keep more than just 1 log entry.
I kept paper logs for a long time- but I can’t tell you how much I appreciate the ability to easily see the all inclusive historical data with the app. Also, no wet paper

As for the Ahhsome purge - it removes the biofilms that attach themselves to the inside of the plumbing. These biofilms are resistant to being broken down by sanitizer alone.
Even brand new tubs often have biofilms in the plumbing due to the fact that they are wet tested at the factory and it’s nearly impossible to evacuate all the water so things grow whilst enroute to you.
This can lead to excessive fc demand right out of the gate. This is why we recommend purging immediately- even though most folks really don’t want to do this step before enjoying their new toy.
So if the water gets iffy, you start noticing increased fc demand or persistent elevated cc’s its time to go on & purge, drain, & refill. We recommend a 3-6 month interval anyway. Some folks are able to go longer but if things get “off” like I mentioned above, no sense in fighting with it. Just start over.