Ideal numbers ?

[saraiks]

There seem to be a general consensus on what the ideal numbers should be for a given pool setup for some paramenters but a wide array of numbers is thrown out for some others.. here is what I could glean from the forum so far for gunnite/Plaster pools with no SWCG

CYA : 50 +/- 10
TA : 150 +/- 50
pH : 7.5 +/- 0.2
CH : 220 +/- 20
FC : 4ppm +/- 1

Comments/ suggestions are welcome

 

[JasonLion]

There are several different ranges for most of the numbers depending on several factors. My suggestions are:

CYA - either 30-50 (normal & ORP) or 60-80 (SWG or lots of sun) or 70-90 (really really lots of sun)
TA - either 70-90 (bleach or SWG or lots of aeration) or 100-120 (trichlor or dichlor) or as low as 50 with borates
PH - either 7.4-7.6 (normal) or 7.6-7.8 (lot and lots of aeration)
CH - either 0 (vinyl) or 100-150 (spa) or 200-400 (plaster, pebble, stone) (fiberglass is unclear, 100+ or 200+?)
FC - depends on CYA, see my Pool Calculator for suggestions (link in my signature)

For a plaster pool I would fine tune the CH level based on the saturation index.

Many of these numbers can go outside those ranges and still be fine and there are a few special situations where other numbers might be required.