FC production calculation

[Jsf721]

The circupool RJ60 makes 3.1lbs per day FC.
From what I understand that running 24x7.

I have a 38,000 gallon pool and 60,000 swg is the biggest they make I was looking for an 80,000 to get 2x per posts I’ve read here.

How many Lbs of FC do I need to make a day to maintain my pool. I understand I may need liquid chlorine added to get me into range but once there what do I need to make to keep the pool in the correct FC range assuming family of 4 regular use.

 

[Texas Splash]

Good morning. While SWGs are advertised with a "lbs per day" rating, and you can see those expectations converted to FC production in our PoolMath APP, FC output can vary when compared to what is advertised. So don't exhaust yourself with precision numbers/expectations or you might be disappointed. As long as the SWG is maintaining a good FC for your pool it's doing what it needs to do. That said, there are several threads of other owners who have installed more than one SWG for their large pool. The link below should help to give you a good starting point.

SWG Multiple Cells - Further Reading

www.troublefreepool.com

 

[duraleigh]

How many Lbs of FC do I need to make a day to maintain my pool.

It is not a constant. It will vary widely by number of swimmers, time of year, etc.

 

[Bperry]

The circupool RJ60 makes 3.1lbs per day FC.
From what I understand that running 24x7.

I have a 38,000 gallon pool and 60,000 swg is the biggest they make I was looking for an 80,000 to get 2x per posts I’ve read here.

How many Lbs of FC do I need to make a day to maintain my pool. I understand I may need liquid chlorine added to get me into range but once there what do I need to make to keep the pool in the correct FC range assuming family of 4 regular use.

I can only say the RJ60 I have makes plenty of chlorine for my 27k pool. I rarely have to turn it above 50% in the summer and it’s only powered on 8 hours per day max. So I think you’de be fine even with the ~30% larger pool.

 

[generessler]

In case you're interested, the calculation is pretty simple. Water weighs 8.34 pound per gallon. So one way to go is convert the cell's output to chlorine ppm for your particular pool:

3.1 lb / (38000 gal * 8.34 lb/gal) * 1000000 ppm = 9.8 ppm

That's what you'd have per day if you run the cell at 100% for 24 hours. And if the cell actually generates what it's supposed to. Reports here vary on that topic.

So just pro-rate that number. If you run 12 hours at 50% it's 12/24 * 0.5 * 9.8 = 2.45 ppm per day. As @duraleigh says, actual demand varies, but this is in the ballpark for daily loss of many pools.

If you use LQ to chlorinate your pool, you probably know how that stacks up with your normal loss rate. But bear in mind TFP and most manufacturers recommend CYA=60 or 70 with a SWG. That slows the loss rate somewhat.

FWIW, the numbers above agree with Pool Math "Effects of Adding" set to SWG and "Free chlorine generated."

 

[jamesey]

Try this:

SWG Run Time Calculator

What is the SWG Run Time Calculator? A tool that is designed to answer the common question of "how long should I run my pump/SWG". It calculates the run time of your SWG and Pump based on your pool size, the output of your SWG and your daily FC PPM loss. It is designed as a starting point...

www.troublefreepool.com