Quote Originally Posted by Rangeball
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/showthr...mical#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!