On Wednesday, June 25, 2014 4:57:46 PM UTC-4, DannyD. wrote:
trader_4 wrote, on Wed, 25 Jun 2014 08:06:58 -0700:
With 4 floaters, isn't the chlorine through the roof?
I understood everything you imply, as I am familiar with
the increasing ratio of CYA to target free chlorine level
as per this common table:
(Stabilizer) (Minimum FC) (Target FC) (Shock FC)
20 2 3 10
30 2 4 12
40 3 5 16
50 4 6 20
60 5 7 24
70 5 8 28
80 6 9 31
90 7 10 35
100 7 12 39
etc.
I've never seen that table. What makes you think it's right?
If you look at the recommendations from the credible organizations,
pool standards organizations, health depts, etc, what I've seen is a recommended range of 1 -3,
with no adjustment for CYA. I know CYA has an effect, in the sense
that while it stabilizes it, it also lessens the sterilizing
effect if it gets too high. If you really need to hike the cholrine way up
there like that, it's strange that I don't see people doing it,
it's not mentioned in health dept guidelines for pools, etc.
I can tell you that 1 - 3 ppm has worked fine here for me for years
over a wide range of CYA levels. No water clarity, algae issues.
There is plenty of full sun here in summer in the NYC area
and with a 48,000 gallon pool, 1 floater loaded with
about 7 tabs keeps the chlorine at about 2 PPM.
I actually only have about 50 ppm CYA, even with adding the
powder, which means I need to target Free Chlorine at 6 ppm.
I think you're over doing that by 2X or 3X. That's why you're
going through hundreds of pounds of trichlor or endless gallons
of liquid chlorine. But it's your pool, if you
want to go by some chart instead of what works, that's up to you.
The question is why you need so much chlorine?
I realize it's not often stated at the pool store, but,
the chlorine number is wholly useless without the associated
CYA value.
If it's so critical then why do public health depts that state
levels for pools just list the levels as 1 -3? IDK of any that
say you need 6PPM or that 6PPM is even appropriate for a residential
pool period.
For example, with your 2ppm of free chlorine, if you had
a 40 ppm CYA, you'd already be below the minimum, and far
below the target chlorine levels for your pool (based on
my read of the chart above).
I think you're obsessed with one chart of unknown background and
ignoring that if it's so important, it would be part of the std
guidelines for pool operators.
AFAIK, it's not. And using 1/3
the chlorie you use works fine here in my pool. I've had CYA at
70, chlorine at 2 or 3 and the water is clear, no algae, etc.
I can only hope, for your sake, that your CYA is at or
below 30ppm, which, for a sunny area out here, would not
be enough stabilizer.
I hope for the sake of your wallet that you reconsider.
I've never seen a pool with more than one floating dispenser,
let alone four.
You haven't seen "my" pool! 
Well, I meant except yours.
Seriously though, I'm welcome and open to ideas, as I can't
seem to keep chlorine in this pool, even though the biological
load is nearly zero (nobody even swims in it lately).
It's not that you can't keep chlorine. It's that you have target
levels that are 2x - 3x too high.
A lot of this pool stuff is just handed down and a lot of it is
wrong. An example is the guideline that you should move the
volume of whatever the pool is through the filter system every day.
Really? The pool in the shade, the pool with a bunch of kids, the
pool in the sun, the pool that's used only one day a week, the pool
where it's windy and debris is blowing in, all have the same reqt?
I've found I can easily get by with half that filtering and it works.
This isn't rocket science, you can experiment and find out what happens.