TA stays the same, even when adding acid daily.

[Arizonarob]

So, I’ve got a question that hopefully you guys can help me understand.
It seems that there are multiple people having the same problem with rising PH, and having to add MA daily to keep it under control. There also seems to be different views regarding where to keep your TA range in to keep your PH stable.
So with that in mind, we know you lower TA with acid and PH comes along for the ride, only to aerate (or just let it drift up on its own) to bring PH back up.
My question is, why doesn’t TA keep going down, if you’re adding acid daily because PH keeps rising???

For me, I’m adding about 3-4 cups of 14.5% MA every week to keep my PH in the 7.6-7.8 range. Surely adding that much acid would take the TA down, but yet it still stays at 70.
How is that possible, and how low on the PH scale would you have to go to force TA lower??

 

[ajw22]

You need to lower PH to 7.0 - 7.2 and aerate to get a good drop in the TA. The more yiu get PH towards 7.0, the more you will change TA. It is not linear.

Getting the PH to 7.0 then knocking it back down when it gets to 7.6 will get results.

 

[mknauss]

What is your fill water TA? You are adding a lot of water right now from evaporation. I am adding about 100 gallons per day to my 6000 gallon pool. With my fill water TA of 140, I add acid twice a week to maintain my TA at 70-80 ---

Take care.

 

[jblizzle]

I agree with the above.
Also, we have a lot of evaporation. What is the TA of the water you are putting back into the pool? That could prevent it from dropping very much.

 

[Richard320]

I find it hard to believe that you don't have to add any refill water in Arizona in the middle of Summer.

 

[pooldv]

I wouldn't call rising pH a problem that lots of people have anymore than I would call people with dropping FC a problem. Rising pH is normal in almost all pools. It is likely that your pH will always rise and your FC will always drop.

But, there are steps you can take to reduce the rise. You can go as low as 50 on TA. Look at the effects of adding chems in PoolMath to see how much the acid you are adding is lowering your TA. As mentioned above, lowering pH to 7.0 will lower your TA faster. More here, Pool School - Lower Total Alkalinity

You can also add borates, after you get your ta below 60 and tha t will also help to slow pH rise. More here, Borates - Why and How

 

[Arizonarob]

What is your fill water TA? You are adding a lot of water right now from evaporation. I am adding about 100 gallons per day to my 6000 gallon pool. With my fill water TA of 140, I add acid twice a week to maintain my TA at 70-80 ---

Take care.

Ok, stand by, going to test it right now.

I find it hard to believe that you don't have to add any refill water in Arizona in the middle of Summer.

Rich, of course my autofill is running all the time. But my autofill is soft water, going to test now.

- - - Updated - - -

TA from autofill is 150ppm.

 

[mknauss]

Water softeners do not remove alkalinity, they remove calcium

 

[Arizonarob]

Water softeners do not remove alkalinity, they remove calcium

Correct, I knew that much.

Fill water TA is 150ppm