# Thread: Pool School vs. Pool Calculator Tool

1. ## Pool School vs. Pool Calculator Tool

What makes you think 5.5ppm FC is too much? It's about mid range for 30ppm CYA (noon time). Are you aware that for 30ppm CYA your target is actually 6ppm?

For a mid day test, that all looks good however if you're dosing only to 5 every day, chances are you're ending the day below minimum which could be why the wife is feeling some sliminess now and then. Try dosing up to 6ppm every night for a week and see what she says.

Edit: Topic split off from http://www.troublefreepool.com/how-i...ol-t36664.html to avoid getting OT

2. ## Re: how is my pool.

Originally Posted by frogabog
Are you aware that for 30ppm CYA your target is actually 6ppm?

For a mid day test, that all looks good however if you're dosing only to 5 every day, chances are you're ending the day below minimum which could be why the wife is feeling some sliminess now and then. Try dosing up to 6ppm every night for a week and see what she says.
frogabog...back to Pool School for you . Please refer to the FC/CYA relationship chart before making correcting statements.

pool-school/chlorine_cya_chart_shock

4ppm FC is the target for CYA at 30ppm. 6ppm is half way to Shock level and only necessary if you are dosing every other day. If you are losing more than half your FC in one day your CYA is either too low or you have organics eating up chlorine. When in doubt, perform the overnight FC loss test to rule out organics.

pool-school/chlorine_cya_chart_shock

3. ## Re: how is my pool.

It's a bit confusing the differences between the pool calculator recommendations and pool school's CYA/Chlorine chart.

I've decided to stick with one source, and pool calculator wins over pool school because I can adjust it to specific CYA levels.

Wrong??

I think recently Jason posted that pool school was more conservative than the pool calculator so those who are shocking get more bang for their buck, but both worked. Two years now of pool calculator dosing has served me well. I have a nice boring clear sparkling pool (unless the fines get stirred up).

???

4. ## Re: how is my pool.

Correct in that Pool School is more conservative. Conservative meaning it typically advocates higher FC levels than those published in the poolcalculator for shock levels. The pool calculator calls the normal FC range for CYA @ 30ppm 2-6ppm. 6ppm is the upper limit of that range, not your target. But if it works for you, that great, it's just you may be confusing folks on this forum by stating it's the target, when it's not. If you are targeting FC of 6ppm and you find your FC falls to 2 every evening, you should consider increasing your CYA level or confirming you can still pass the overnight FC loss test. Losing 4ppm FC per day is a tad high

5. ## Re: how is my pool.

Gotcha, that's what I thought Jason said. However since pool calculator calls 2 minimum, and 6 target, I tend to use those terms and stick to them for my own dosing.

At 40ppm CYA I loose anywhere from 1-3ppm daily depending on if the sun peeks out or not. So, dosing to 7 at night leaves me around 4ppm the next day on average.

Good?

6. ## Re: how is my pool.

That sounds about right (1-3ppm FC loss) at 40ppm

For clarity, within http://www.poolcalculator.com you set your own target in the target column. The suggested FC level of 2-6ppm FC with CYA at 30 is the "normal" range, not minimum or target.

7. ## Re: Pool School vs. Pool Calculator Tool

Woot! Clarity... clearer :~}

Thanks. I see what you mean. I use the high number in the target column for dosing and the term stuck. Well I used to... now I simply count 1c 2oz as 1ppm and raise it as my night test indicates.

I will cease to use the term "target" for high end of normal range from now on.

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