High PH wont come down

[drober30]

The PH level of my tap water is 7.0.  

I filled my tub and balanced my TA then Calcium Hardness. I then tested my PH and it was very high.

Using a Taylor test kit I did the Acid Demand test. It took three drops to bring it into range. That equaled about three tsp of PH decrease.

I added the PH decrease and the PH was still above 8.0 (I waited several hours before testing).

I added another three tsp and after testing today the PH was still high. I ran a sample up to the dealer and they said it was at 8.2

I just added another three tsp of decrease and will check again tomorrow.

I usually battle low PH.

What could have made my PH so high when it's 7.0 from the tap?

Why won’t it come down?

[Chas]

You should toss in about two dry ounces of pH decreaser ("Spa Down" or similar) very quickly or you are likely to be looking at a calcium fallout. That's where the inside of the spa starts to feel like sandpaper.

[tony]

Three drops for a 400 gal spa equals 1.5 oz dry acid.  That is nine teaspoons.  You need to keep adding...as Chas says...quickly.

[hottub.pool_boy]

is your sanitizer level high? it can scew the ph test. your taylor kit should come with neutralizer.

the alkalinity increaser also raises ph as a side affect.  

[drober30]

I only added 1 tspon dichlor to start the silver ions. I will keep adding decreaser as suggesting.

Everything else is in range, TA, CH...  

I have no idea what caused this...

I'll report back after testing

[windsurfdog]

The PH level of my tap water is 7.0.  

I filled my tub and balanced my TA then Calcium Hardness. I then tested my PH and it was very high

What was your TA before you adjusted it initially?  What was the pH before you adjusted the TA initially?  Even though your tap water is 7.0, adding aeration to new tub water will drive the pH up--I bet your pH after a day or so was a bit higher than 7.0.  My tap water is 7.4 but after the first day in the tub, pH checks out around 8.0 or so.  Sounds like you added quite a bit of sodium bicarb to raise TA which also raised pH and now you are adding dry acid to bring the pH down (which will also lower TA).  If this is the case, I think you should have concentrated more on pH than TA initially.  To help now, when it's time to shock, use unbuffered MPS with its pH between 3-4 to also help bring pH down.

[drober30]

What was your TA before you adjusted it initially?  What was the pH before you adjusted the TA initially?  Even though your tap water is 7.0, adding aeration to new tub water will drive the pH up--I bet your pH after a day or so was a bit higher than 7.0.  My tap water is 7.4 but after the first day in the tub, pH checks out around 8.0 or so.  Sounds like you added quite a bit of sodium bicarb to raise TA which also raised pH and now you are adding dry acid to bring the pH down (which will also lower TA).  If this is the case, I think you should have concentrated more on pH than TA initially.  To help now, when it's time to shock, use unbuffered MPS with its pH between 3-4 to also help bring pH down.

This makes good sense... my TA was low like around 75 and I did add TA increaser, a decent amount, I don’t remember the exact amount but it was several TBS, like nine of them. That must have been the culprit.

I have always had to adjust my TA up after a refill and never ran into this problem but maybe I did not have to add as much. Maybe the water levels at the tap changed sense my last refill.

It's coming down because I only need one drop in the Acid Demand test to bring it into range.

When I use Dichlor my PH is always low.  so wont adding dichlor also bring down my PH?

[hottubdan]

Adding dichlor will help lower pH over time.

[drober30]

Adding dichlor will help lower pH over time.

I thought so because:

I was used to (low PH) and increasing it was easy.

My routine was:

Balance water from the start in this order - TA, CH, PH

Then add 2 tsp of dichlor after using tub.

Add 2 tsp dichlor every two days of not using the tub.

Add 6 tsp of dichlor weekly for shock.

Check all levels weekly with Taylor Test kit.

Check dichlor level with test strips to make sure my routine is keeping the right amount of dichlor in tub before soaking.

I think this is the routine many use on this forum?

However, I'm thinking of trying the MPS before use and shocking with dichlor weekly.

Along with the ozone and silver ion, this is what my HS manual calls for when using the Fresh Water III program (ozone, silver ion, MPS).

This way I can evaluate both methods myself to compare smell and water quality.

The one thing I liked about straight dichlor and no MPS was the safe feeling of always adding sanitizer.