FC level help

[txsteel]

I want to avoid issue before they happen so I would like some input of what to set my SWG to. This week has been difficult to check everything as I have have been leaving the house at daybreak and not getting home till dark.

My FC was at 3 last Saturday and I measured it Monday night where FC= 1. My SWG was set at 50% for 10 hrs run time. I bumped it up to 60% same 10 hrs. I tried to measure it early this morning and I believe my reading was about 2.5. I've been using the pink powder method provided in my TF-100.

Any input or tips is appreciated.

Other info
~15000 gal SW pool
Water is clear and looks great. (only early morning and night with light on observation)
temp ~85
PH = 7.6
TA = 80
CH = 190
CYA = 70
salt = 3800

P.S. I would love it if all the test were not red and green related as it is difficult when you are red and green color blind.

 

[JasonLion]

Measure the FC level at the same time of day every time, preferably early evening. The FC level will naturally fluctuate through the course of the day. Testing at different times can throw things off because of that.

It also matters quite a bit how sunny it was. The best days to test are days that have been very bright and sunny. Also, days when you had an unusually large number of people over to swim are not good days for calibrating the percentage.

 

[txsteel]

Thanks Jason. I understand the effects sun and activity has on FC and measurements as well as trying to be consistant on when to take the measurements. This week is an exception to my norm.

Let me rephrase my question.

I am not new to pools, but to SWG, so I would like so advise on settings. how long to run the pump and what percentage. should I start at to try and maintain a good FC level.



~1500 gal
Full sun for ~10 hrs
IC20 SWG

 

[ping]

If I'm doing the calculations correctly, you are only adding a little over 1 ppm of FC with those settings. To get about 2.5 ppm of FC, you need to run at 100% for 10 hours a day. For a 2.5 ppm raise you need 4.9 oz of chlorine gas. Your SWG can produce 11.2 oz of chlorine in 24 hours running at 100%.

The chlorine you need for 2.5 ppm a day is calculated this way, 4.9/11.2=.4375. Take this number and multiply it by 24 for hours in a day and you get 10.5 hours of run time at 100% output to generate 2.5 ppm of chlorine for your pool.

Raise the FC level with bleach to help the SWG for now. You might want to run an OCLT just in case there might be something in there that you can't see.

The cell you have is on the small side for your pool size.

 

[txsteel]

Thanks ping. I'll perform an OCLT