New Water/Refill

[h20man]

just refilled my pool , got the ALK up to 100 & now the PH is sky high....poured in 1/2 gall of Muriatic Acid , didn't seem to change it, so I dumped the rest of the gallon in ...is it normal for PH to take a while to drop after a new refill? Guess it depends on the water ....

[duraleigh]

...is it normal for PH to take a while to drop after a new refill

Probably not. How high was "sky high"? Perhaps you have not yet dropped it within the range of your test.

[doggie]

How high is your free chlorine? Sometimes a really high chlorine level will make the ph test result abnormally high.

[Simmons99]

You didn't mention if this was a concrete pool - is it a new finish - did you just have the finish acid washed? That may make your PH rise considerabely everyday until the finish has cured.

How long are you waiting from the time you add the acid until you are testing the PH again - is it the next day, 10 minutes, an hour? I add acid with the pump on and then brush the whole pool - it takes about 20 minutes and helps to stir things up - then I retest.

Also how large is your pool - I find with ALK of 80 in my pool - it takes about 2 cups to go from 7.8 to 7.4. The larger the change in PH - the more it will take - and the larger the pool the more it will take.

I would refrain from adding a whole gallon at once - I wait a day between additions just to verify a reading wasn't bad due to the pool not being mixed up yet.

[h20man]

yes it was acid washed...

PH - 7.5
ALK - 80 (just dumped more soda)
CL - 2PPM
CALC - 50
CYA - 20

concrete pool 20k gallons, pebble sheen surface


looking to get the CL up tonight & then start on the CYA & CALC

thanks!

[Simmons99]

You could have a rising PH due to plaster dust in the pool. Your numbers look fine - you could add a little more CYA to hit about 30ppm - but your chlorine should only need to be around 3-4ppm at a CYA of 30.

ALK at 80 is fine also - if you get this higher it will tend to raise your PH - so if it is stable at 80 - just leave it alone. My pool has ALK at 75-85 depending on whether PH is 7.2 or 7.5.

Just test the PH once a day and add SMALL amounts of acid to drop it a couple of points at a time. I add about 2 cups to the pool about every 3-4 days now - at first it was daily.