anyone using hamilton index for water balance?

[J.C.McGILLICUDDY]

I have a Bromine generator system by genesis.I have a hard time keeping my ph down and it always goes back to 7.9-8.0.I'm pretty sure it's a result of the system generating Bromine.I'm interested if anyone is using the hamilton index for their water balance and your thoughts and any problems you've had using it.I'm a little concerned about scaling on my heater and plumbing as it tells you to maintain a ph between 7.6-8.2 I have soft water with no metals and i bring my ch up from 35ppm to 150 ppm.this leads into another question.The Hamilton Index tells you to measure the total hardness of the water not the calcium hardness.Do the test kits using drops measure the total hardness of the water and we just use calcium to bring the hardness up? or is this a different test altogether? thanks for any help in this regard J.C.

[Electro]

J.C.

You will get your best answer by going to www.rhtubs.com and addressing your questions to Northman and/or Vermonter.  They are experts in this field of spa chemistry.

Northman has written extensively on why calcium hardness is unnecessary in modern hot tubs.  He runs tubs with soft water.  He says only if you have a concrete pool or spa or metal parts do you need to raise calcium hardness, primarily so that the calcium in the concrete is not leached out and metal is not corroded (and only under low pH conditions below 7.4).  See the FAQ section at that web site for details.

You will get scaling at pH above 7.8 with the levels of calcium above 90 ppm.  If you meticulously maintain pH at 7.5 with TA between 100-130 ppm, there will be no problems, even with soft water (calcium below 50 ppm).  The advantage of soft water is that scaling is virtually impossible.