Drain & Fill Question

[CarlD]

Richard:
I'm aware that if you drain off 200 gallons, then refill, your concentration of CYA changes. The next 200 gallons you drain will have a lower concentration so the refill will give you less "bang for the buck".

I deliberately decided to ignore that problem as it soon becomes an exercise in differential calculus--which I never use for fun or hobbies! I deliberately kept it SIMPLE for clarity.

I wanted to get to the REAL point: with excessively high CYA you cannot try to drain a little, then add a little to be effective.

Sometimes, trying to be very, very accurate causes you to obscure the REAL message and the real answer, so you have to watch for a "forest and the trees" situation: With excessively high CYA, if you want to lower it you must do a large drain and refill. Period.

The object is to give NJPool an effective option.