Need advice on best TA level

[zimm27]

I have a newly built pool and am working on getting the chemicals balanced. So far, things are pretty good. The TA was a bit high at 170 originally but I have gotten that down to 120. As of last test I was at:

FC: 3
CC: .5
TA: 120
CH: 310
CYA: 30

Reading the guide info on the Pool Calculator it says:
The ideal TA level depends on several factors. If you are using acidic chlorine sources, such as trichlor or dichlor, keep TA on the high side, perhaps between 100 and 120. If you have a SWG, or if you commonly run water features such as a spa, waterfall, or fountain, keep TA on the low side, between 60 and 80. Otherwise levels between 70 and 90 are good. Pools with plaster surfaces should factor their CSI into the preferred TA level decision.

I have a trichlor tablet feeder, but I also have 4 spillway water features that we like to run a lot. I am not sure whether I should shoot for the 100-120 or the 60-80, or shoot for somewhere in the middle. I plan to add borates to the pool soon so I want to get the TA balanced to a good level first. Is there anyone that either knows or has a similar pool setup that can advise on what the best TA level has been for them to keep pH manageable? I have read that it will be harder to adjust after adding the borates.

Whether it matters or not, I am going to monitor the CYA to see if I have a problem with the trichlor chlorine source, then possibly switch to bleach or a "The Liquidator" if that proves to be necessary.

Thanks!

 

[jcowart]

Whether it matters or not, I am going to monitor the CYA to see if I have a problem with the trichlor chlorine source, then possibly switch to bleach or a "The Liquidator" if that proves to be necessary.

Thanks!

Just a little note on the CYA. For a 20,000 gal pool, a 25# bucket of tabs will raise the CYA by 83 on top of your 30 that you already show.

 

[pwrstrk]

Every pool is different, meaning somebody else's TA may not be ok for your pool. Your TA is usually in a good spot when you have a fairly stable PH or a slow increase in PH. The TA may be out of a so called range but if the PH likes it then it's in range.
My suggestion is to manually add the stabilizer and switch over to bleach. Makes things a lot easier and there is no side effects like you have from the pucks. Save the pucks for when your on vacation.
If you do decide to stay with the pucks just make sure to stop using them before the CYA gets out of range.

 

[JamesW]

Probably the easiest way to get the TA right is to keep adjusting the pH without regard to the TA. As you adjust the pH, the TA will get closer and closer to the perfect level for your pool, and the pH will pretty much lock in and need minimal adjustment.

 

[anonapersona]

In Texas we can assume that you will keep the pool open year-round. Your DE filter will cause some water usage while cleaning and running the water features will cause rather a lot of water usage depending on the temp and wind in your area. So you can expect the pool to always be tending toward the TA you saw with your fresh fill at 170 ppm as you add water to top off the pool. (Actually, your fill water may be higher that 170 Ta if there was any residual acid in the pool but let's ignore that or just test fill water to know the facts.) So, just expect that TA will always tend to rise, no matter what you manage to lower it to. And as it rises, pH rises as well. You don't actually care about TA but you do care about pH as that impacts swimmer comfort.

This means that you will always be adding acid one way or another to control pH. You can add acid manually, with Muriatic acid or dry acid, or automatically, with some sort of dosing system, or via tablets.

If you can ever get to a TA of 60 - 70 you might find that pH becomes quite stable and if you normally will use bleach this would be your target. Personally, I've only gotten the pool there momentarily. It helps to have a lot of rain, while refilling the pool hurts due to the fill water. If you know that you will be going on vacation and want to use the tablet feeder for that time, you would let the TA rise some in advance of the vacation toward 80 or 90 or 100. IME, using tablets has reduced the TA by about the amount of CYA added, so that in 2 weeks TA will drop by about 20 ppm. Given that 60 - 70 is a minimum TA, for pH is crazy unstable (up or down) at below 60, you will want to bear that in mind when switching to tablets. But, really, I'll be surprised if you can get TA that low without a monumental effort. I am happy when it gets below 100.

Meanwhile, my pool still has CYA of 45 at last test, in spite of a wet winter. The TA is still high at 100, and with a long vacation coming up, I'm stumped as to who I can trust to manage the pool for I cannot use tablets with these values and so it will require bleach and acid, unless the CYA has magically dropped in the last month.

 

[BoDarville]

Your TA is usually in a good spot when you have a fairly stable PH or a slow increase in PH.

This really sums it up nicely and succinctly. When your pH stabilizes with little or no drift, you have found the TA happy medium for your pool. Use that criteria as your TA yardstick and don't get hung up on targeting a particular TA number.

 

[bear31088]

Is there a similar balance or different values for a fiberglass pool or does it matter? I've been trying to get thbalance but so far it's been tough. Current values are:
FC 7 CH 280
CC 0 CYA 60
PH 7
TA 80

 

[duraleigh]

I've been trying to get thbalance

I don't see anything wrong with the numbers you have posted. What does your water look like?

 

[bear31088]

thanks for the feedback; I appreciate it. The water is crystal clear.

 

[anonapersona]

I sure don't want to contradict Duraleigh, but I will note that your kit will not test pH lower than 6.8 so you want to be careful that you do not drift in that direction. And CYA is a bit above ideal, but probably fine for your location, just don't want to go higher.