PH will not go down

[jrogers]

I received my new TF 100 test kit my readings for the last three days are:

FC 4
CC 0
PH 8.0
TA 110
CYA 30

I can not get my PH down. I have added 5 pounds of dry acid but my PH is still at 8. Should I adjust the TA down first?

 

[tim5055]

Keep slowly adding acid. You may be up above 8.0 and at the limits of the test. Keep slowly adding acid until you see the drop in pH.

 

[jblizzle]

As Tim said, you have to just use PoolMath to determine the amount of acid required to reach your target and add it. Then test in 30-60 minutes and see if you hit the target or if you need to add more.

BTW, it is usually advisable to use muriatic acid instead of the dry acid which add sulfates to the water.

Also, you can not lower the TA without lowering the pH ... they are related to each other and your TA is really not that high anyway.

 

[Tepelus]

One has to remeber that pH is a logaritmic scale. Close to pH 7 a certain amount of acid will make a much bigger change than at pH 8.