Bleach and higher PH

[Rangeball]

Since chlorine is not as effective a sanitizer the higher the CYA levels, you need to add more chlorine, ala Ben's "Best Guess" table.

Since chlorine is not as effective a sanitizer at higher PH levels, does there need to be a "best guess" table for PH as well?

I wonder if the pools that run high PH in Ben's "high PH" article run chlorine at higher levels because of this?

I also wonder if pools running high CYA AND high PH get a double whammy on chlorine effectiveness?

[Bleach=Chlorine?]

Rangeball,
Not sure if this is in response to the post from yesterday but a member posted an issue regarding the pool not clearing up. Not sure about the accuracy of the #s but they had a pH of 8.4 and CYA between 100-150. It would be nice to have a calc where you could plug in pH, TA and CYA and it would give you the 'effective' factor of Chlorine.

[waterbear]

chlorine just isnt as effective at high pH....the solution is to fix the pH, not add more chlorine!

[day1]

the bleach raises pH, and so you have to lower w/ muratic or dry acid....all the while using borax/baking soda to balance alkalinity so you actually use less chlorine and acid, if possible.

[Rangeball]

chlorine just isnt as effective at high pH....the solution is to fix the pH, not add more chlorine!


Then why is Ben (apparently) and others in his article running pools at high PH?

Seems contradictory.

[waterbear]

Then why is Ben (apparently) and others in his article running pools at high PH?

Seems contradictory.
This is a quote from Ben's page on high pH pools from the pool solutions website (empahsis mine):

"However, high pH often will also tend to
precipitate metals in pool water, such as copper, iron or manganese
lower the measured ORP for a given DPD chlorine level (only important if you have and ORP controller on your pool)
increase the time required to kill a particular pathogen with a given DPD chlorine level (eg, the Ct value for a given DPD chlorine level)
make broadcasting of calcium hypochlorite (HTH) to your pool problematic.
increase scaling if your calcium and alkalinity are too high."If you go and re read the article you will find that there is no contradiction at all. High pH pools have advantages and disadvantages....

Also here is a quote from PoolDoc (Ben) from this very long thread:
http://www.poolforum.com/pf2/showthread.php?p=3891&highlight=united+chemical#post3891

"These facts may explain why I try to de-emphasize the Langlier and Rynar indices. The Hamilton index is really a rough, seat of the pants, index that was mainly designed by Jock Hamilton of United Chemical, so those who 'had to have' an index, had one. It favors high pH, because high pH favors the bromine chemistry that's in virtually every product United sells."

IMHO, high pH pools do have some advantages and some disadvantages. You just have to weigh them!

[Rangeball]

After posting my last comment, I did go back and re-read the article, and caught that.

Thank you :)


Rangeball,
Not sure if this is in response to the post from yesterday but a member posted an issue regarding the pool not clearing up. Not sure about the accuracy of the #s but they had a pH of 8.4 and CYA between 100-150. It would be nice to have a calc where you could plug in pH, TA and CYA and it would give you the 'effective' factor of Chlorine.

Not in direct response to that thread (although I think that was a good call on your part), but other stuff I was reading. I agree such a calculator would be nice.

[Bleach=Chlorine?]

Yes, I was not advocating running at high pH but it would be nice to know what pH and CYA do to the effectiveness of cl.

[cwstnsko]

Over in the China Shop there's a thread about an index that specifically discusses the effectiveness of Cl at various pH levels. It's not a "mainstream" index, but it explores one person's theory.