New Test Results

[Hyo]

Ok I drained and refilled about 45% of my pool water and here are the results:

TA=120
pH=8.0
FC=8.0
CC=0
CYA=70-75
CH(Pool)=700
CH(Fill Water)=200

So I know I need to get some muriatic acid in the pool to lower the pH and TA then aerate and repeat, but I'm not sure how to tackle the high CH. I would prefer not to drain anymore water at this point. Can I add something to lower CH?

Also is this calcium scaling?

 

[Hyo]

Lets try that again.

Is this Calcium Scaling?

 

[PaulR]

For both CH and CYA, there are really only two ways to lower them: remove water and replace it with water that has less of whatever you want to get rid of; or, a reverse osmosis treatment.
--paulr

 

[waskydiver]

Is there a theory as to how your CH got so high?

I would say that if you know how your CH got so high, and you have changed whatever it is that was making it so high, then you may be able to get away with leaving it be.

But... you will need to make sure that you can consistently, and without fail target a lower pH. No higher then, say 7.4. That includes in the winter, when the pool is closed, when you go on vacation.

I would recomend another drain (wouldn't hurt to get your CYA a little lower too). But if you are comitted to not doing so, I would:

Bring your pH down to about 7.2, and do not let it go above 7.4ish.
Bring your TA down to... say... 60.
Add some borates to give yourself a little non-TA buffer. (This will add to your CSI, but not as much as TA).

Then see where your pH likes to rest. If you are not struggling to keep it between 7.2 and 7.5, you may be OK for awhile as your CH drifts downwards.

If it's a struggle, then I think you would need to do a refill.

 

[Hyo]

Argh! before I drained, my pH would constantly drift upward. I assume the previous owner who used trichlor pucks never drained the pool so that's how the CH and CYA got so high. I really didn't want to do another refill, but I guess it would be for the best at this point. Does anyone know why my plaster has that light blue build up in the picture above? Thanks All.