What happens if you get PH lock?

[squale]

It seems that my PH has locked at around the 6.7 range and my total alk is around 140  

what does it mean when the PH locks?  is there a way to fix it or do you need to change the water?  I use Dichlor btw..


thanks

[Hillbilly Hot Tub]

What are you using to raise the PH? Are you using just ALK increaser(ie baking soda?)

[squale]

it's called SpaGuard PH Increaser

[hottubdan]

You are using the right stuff, sodium carbonate.  How much are you using?  How many gallons do you have?  How old is the water?  Do you live somewhere where it is not frozen so you can change the water if needed?

So many questions...

[squale]

live in jersey it's frozen here!  been 3 months on this water thus far..  use only Dichlor every day, MPS once a week and run an N2 cartrige too.  375 gallons, Sundance Altamar spa with ozonator.  Spa is in my two car garage.

it seems lately that my Alk was high, so I lowered with PH decreaser.  Alk is now around 100 ppm, but PH is low around 6.5.  Just added 3 tablespoons of PH increaser this morning.  Hopefully that will raise the PH into the 7.2 range but then my Alk is probably going to go way up into the 170ppm range again.  I can't seem to keep the Alk low and get the PH higher without affecting both!

[Hillbilly Hot Tub]

Airating the water will help raise the PH without raising the ALK.  The other issue you may have is your CYA. If you use Di-chlor daily, in 3 months the CYA will be high, thus your chlorine will not be effective in sanitizing and this may be the cause for your PH issues. What is your CYA reading?

PH and ALK will both be affected when adjusting them, nothing you are doing wrong. They can become somewhat of a pain at times depending on what else is going on in the water.

[squale]

yeah I should go get my water tested.. my aquacheck digital doesn't do CYA testing..

so I guess I should run the tub with the air blower for the air bubbles on for a while?