Target FC for SWG - Pool School Recommendation or PoolMath?

IsaacFL

Active member
Jan 2, 2015
29
Palm Springs, CA
Trying to figure my FC goal:
SWG 70 for CYA

recommendation according to Pool School at http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

CYA (Stabilizer) 70
Minimum FC 3
Target FC 5


However, if I use Pool Math, set for SWG, Plaster, it recommends:
CYA (Stabilizer) 70
Minimum FC 3
Lower Target FC 8
Upper Target FC 10

Which target should I be using? I had always been using the Pool School Target of 5, but noticed PoolMath is recommending 8-10. Has something changed?
 

IsaacFL

Active member
Jan 2, 2015
29
Palm Springs, CA
I notice that changing the Pool Math from SWG to Bleach or anything else for that matter does not change the Target Range, so probably a problem with PoolMath.

I think I am going to follow Pool School recommendation of 5 FC, unless I hear that there has indeed been new thinking on this.
 

ping

TFP Expert
LifeTime Supporter
Jun 24, 2011
2,940
Long Beach, CA
The main thing is you just don't want to go below the minimum level at any time. Targeting 5 will most likely ensure that the level will not drop below 3 anytime during the day.
 

duraleigh

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Mod Squad
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In The Industry
Apr 1, 2007
31,514
Sebring, Florida
The guidelines on TFP are developed and modified slowly as anecdotal evidence from members' reports is ultimately the best way to set standards.

Because of this, our guidelines are a bit fluid and you will find some suggested levels that don't match perfectly.

In every case, either level is fine. Pool chemistry is not a black and white issue wherein your arms and legs fall off if your pool chemistry is not PERFECT in every regard. It's important to learn the ranges and the possible results if your pool drifts outside those ranges.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
37,433
Tallahassee, FL
Each pool is SO different. It is best to keep a journal of your test results so you can see what works best. Do you have FC at the end of the day? If no then you need it higher to start with. If too much FC then you need to lower it. As Dave says it is fluid so it can fit many pools.

Great question!

Kim:kim:
 

IsaacFL

Active member
Jan 2, 2015
29
Palm Springs, CA
Each pool is SO different. It is best to keep a journal of your test results so you can see what works best. Do you have FC at the end of the day? If no then you need it higher to start with. If too much FC then you need to lower it. As Dave says it is fluid so it can fit many pools.

Great question!

Kim:kim:
I have always kept my FC in 5.0 -6.0 range since I run the cell during sunlight hours and FC doesn't go up and down as long as cell is at right level. But pool math says I should be keeping it at least 8? It seems it will be hard for my cell to keep it that high, so should I lower the CYA and ignore the SWG vs bleach model that was put forward in Pool School and just use the bleach table?
 

Leebo

Admin
TFP Expert
LifeTime Supporter
Jul 21, 2011
8,184
Eastern Ohio
One issue with PoolMath is that we have to create one form to fit all pools. As you can see here it can become confusing trying to include all the information to fill all the different scenarios.
PoolMath.jpg

Above is a screenshot of PoolMath for your CYA level of 70ppm. As you can see in the very first box you're given the "SWG Minimum" of 3 which matches Pool School. Go with that number as the one you do NOT want to allow it to go below. The reason we suggest 5ppm in Pool School is it's a good target to help make sure your levels are always above 3ppm. The 8-10 comes into play when you are not using a SWG as those levels are higher. Ignore that box unless you dose manually with Liquid Chlorine.......it's simply there to fill different scenarios.
 

dzedaddy

Active member
Jul 9, 2017
26
Clayton, NC
Wait, the Daily Target in PoolMath is intended for non-SWG pools? Can I suggest we add a statement in there, as I have been confused on this point.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,195
Tucson, AZ
I think I could make this more clear with a very simple fix if you like Lee. Seems this question keeps coming up.
 
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