CYA in a Bromine Pool

[CarlD]

Nope. A table like the "Best Guess Table" only a "SWCG Best Guess Table".

[waterbear]

Nope. A table like the "Best Guess Table" only a "SWCG Best Guess Table".

For an outdoor pool with a SWG:
CYA 80-100 ppm (use SWG manufacturer's max number)
FC 3-5 ppm
Shock, if and when needed to 20 ppm with bleach

These numbers work.

I would also add:
TA 60-80 ppm
pH 7.6 to 7.8
CH 350 to 400 ppm (for plaster and fiberglass)
borates 50 ppm

These parameters will give the best pH stability, which will vary with each pool because of such variations as water features, assuming cured plaster.

No need for a chart since keeping the CYA at 80 or 100 ppm is important for pH stability since it translates into less cell on time.
One set of parameters is all you need based on the CYA of 80 or 100.

[CarlD]

That's a really, really small table, 'Bear!

Reminds me of the world's shortest poem called:

"Fleas"

Adam
Had'em.

[waterbear]

That's a really, really small table, 'Bear!

Well, It's all you need!

[chem geek]

I remember there was at least one SWCG pool owner who tried to use 3 ppm FC with 80 ppm CYA, but that wasn't enough to prevent algae growth. So the minimum recommendation is closer to an FC that is 5% of the CYA level (rounding up from my original 4.5%) so 4 ppm FC with 80 ppm CYA or 5 ppm FC with 100 ppm CYA. This is already lower than Ben's Min. FC for manually dosed pools, but going any lower than this may risk nascent algae growth.

[waterbear]

I have been running 3 ppm FC with 80 ppm CYA but I do maintain 50 ppm borates so that might account for it.

[chem geek]

Yup, the borates definitely take the edge off of algae growth as I've noticed in my own pool. This is consistent with the data in the text and in Table 18 in this link where 50 ppm seems to give a 50-70% inhibition in the rate of algae growth.