TA/pH Offsetting Each Other

[DaHolla]

I'm new to all of this (just moved into a new house that came with a hot tub) and I feel like I'm losing my mind. My pH has been consistently high, and adding dry acid has slowly been getting it down. However, once I get close, the next addition seems to take me too low. So I add some baking soda and end up right where I started with pH that is too high.

For example, today I got my TA to 80, which had my pH at about 8.4. I slowly added acid throughout the day, got the pH down to about 7.7, but by then TA was around 30. So I added a small amount of baking soda, and now I'm back at 8.4.

My hypothesis is that something else is out of balance, but I don't even know where to start. The guy that came out and got me setup gave me a Taylor K-1003 kit, which apparently is lacking several tests. I'll look at getting the TF-Pro Salt, but is there anything I can do in the meantime?

Thanks in advance for the help!

 

[Bperry]

I'm new to all of this (just moved into a new house that came with a hot tub) and I feel like I'm losing my mind. My pH has been consistently high, and adding dry acid has slowly been getting it down. However, once I get close, the next addition seems to take me too low. So I add some baking soda and end up right where I started with pH that is too high.

For example, today I got my TA to 80, which had my pH at about 8.4. I slowly added acid throughout the day, got the pH down to about 7.7, but by then TA was around 30. So I added a small amount of baking soda, and now I'm back at 8.4.

My hypothesis is that something else is out of balance, but I don't even know where to start. The guy that came out and got me setup gave me a Taylor K-1003 kit, which apparently is lacking several tests. I'll look at getting the TF-Pro Salt, but is there anything I can do in the meantime?

Thanks in advance for the help!

Welcome! You’ve discovered the pool store merry-go-round that lets them sell you acid and expensive baking soda. The TA is fine down to 50ppm and will also help slow the pH rise when it gets there.

Also if you have a salt cell, beware of dry acid. The sulphate buildup over time will destroy the cell. Better to muriatic acid instead.

 

[PoolStored]

I'll look at getting the TF-Pro Salt, but is there anything I can do in the meantime?

Welcome to TFP!!!

Lots of stories about getting pool stored. Link-->I knew I was Pool Stored when...

Get the kit ordered now. It will save you many $$ and heartache.

pH won't matter for the moment if it is a bit high until you get your kit.

Post up results when it arrives. We'll help!

Read a bunch in the meantime:
Pool Care Basics
FC/CYA Levels
PoolMath

The result...Link-->How Clear is TFP Clear?

 

[sande005]

You also may be too quick to judge - give the additions some time to mix and do their chemical reaction thing. Test several hours after a chem addition for pH/TA.
Aeration of the water will naturally raise pH - so your water features likely are contributing to that rise. One normally will not have to chase TA. Acid additions to keep the pH in check will normally lower the TA a small amount too. But it will take a while. As TA gets lower, the pH rise will be less. Without aeration, many pools will tend to stabilize in the high 7's. With the hot tub aeration, you may eventually have to add some baking soda to get TA back up - but it will be after a prolonged time.
Use hardware store muriatic acid, rather than dry acid. Cheaper, and no issue with salt generators.

 

[PoolStored]

Test several hours after a chem addition for pH/TA.

Depending on your pool's circulation, the pH change should be reflected in 20-30 minutes with the pump running. If you feel the need, wait an hour to be sure. Most chemicals mix thoroughly in the pool rather quickly and the reactions in the chemical buffer system are very fast (in human terms).

 

[ajw22]

The OP says he/she has a hot tub not a pool.

A hot tub may have an ozonator that will affect the pH after a few hours.

PH matters. A low TA does not matter if the pH is stable. TA of 30 can be ok in a hot tub if the pH is stable. Don’t adjust the TA to reach a number. Low TA and pH in the high 7s is fine.

PH and TA will drift around over time. Especially in a hot tub that is a small body of water and may have automatic controls running equipment that affects the pH. You cannot lock in numbers.

 

[phonedave]

Stop trying to adjust TA. You will never win.

A hot tub is a lot more "touchy" than a pool (it is a MUCH smaller body of water).

When I do a water change in my hot tub, I add acid on a daily basis for 7 to 10 days. I get my pH to 7.2 or so, and then the next day it has risen to 7.8 or so, so I add some acid to get it down to 7.2 or so.

One day, the pH has not risen to 7.8, but it around 7.5. The next day it is STILL at 7.5. That is where I measure the TA and say "huh, so that is where my TA needs to be". As long as it is not totally out of whack, that is where it stays.

 

[DaHolla]

Thanks for all the great feedback, this seems like an awesome community!

I was a bit conflicted on muriatic acid, but it seems like this is the right way to go with a salt cell.

TF-100 has been ordered.

A few mentions about chasing TA. The reason for this is that steady additions of dry acid would result in high pH to low pH, almost instantly. A drop test confirmed TA of 0, so I've been overly paranoid of doing that again. Although a TA increaser instantly put me back in ~8.0 pH range.

Thanks again for the information, anecdotes, and advice. For now I'll keep adding acid until I can get to a decent range, while I wait for the new test kit.

 

[Bperry]

Thanks for all the great feedback, this seems like an awesome community!

I was a bit conflicted on muriatic acid, but it seems like this is the right way to go with a salt cell.

TF-100 has been ordered.

A few mentions about chasing TA. The reason for this is that steady additions of dry acid would result in high pH to low pH, almost instantly. A drop test confirmed TA of 0, so I've been overly paranoid of doing that again. Although a TA increaser instantly put me back in ~8.0 pH range.

Thanks again for the information, anecdotes, and advice. For now I'll keep adding acid until I can get to a decent range, while I wait for the new test kit.

Don’t add anything until you get a new test kit. A TA of zero would put the pH very very low. Never allow the pH to get below 7.0.

 

[Mdragger88]

@DaHolla
A little goes a long way in a small tub. Aka - there is less room for measurement errors.
Always Use PoolMath for calculating additions and cut them in half if you need to. You can always add a little more if necessary.
Ph anywhere in the 7’s is fine.
High 7’s is fine. Even hanging out at 8.0 for a bit is ok. Don’t rush to lower ph by so much. This will help you avoid tanking your ta.
Also, try testing your ph after things have been calm. Not while the jets are raging.
Be sure that you have an adequate water level (covering all jets) to reduce turbulence (and subsequently ph rise) during standby.
You may also find it helpful to adjust/reduce your circulation/filter cycle frequency if possible to help reduce ph rise caused by aeration during standby.
After all these methods have been employed & you get the hang of managing your ph you may want to try adding borates (via boric acid) to help reduce ph rise frequency some.

Borates in pool - Further Reading

www.troublefreepool.com

 

[JoeSelf]

If not mentioned already, you can turn off your air to the Jets if you are able when you're not in the tub. This helps lower the effects of aeration when your tub runs automatically and you are not in there. This is what I do.