Help me plan my runtime - IC40 w/ VSF

Candurin

Well-known member
Jun 30, 2017
301
South Jersey
Pool Size
13000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
So this week I am manually controlling chemistry with liquid chlorine (10%), stabilizer, MA, etc.

Pool water is 60 degrees. Once I have it dialed in, I want to throw the salt in the pool, targeting 3400-3600ppm and fire up the IC40. It’s currently set at 0% output.

According to pool math, I can run my IC40 at 20% 24/7 to get proper FC. I was planning on running my pump 24/7 at the lowest RPM that gives me good SWCG flow.

Is this the right approach? How do I best maximize pump runtime at lowest flow (cost savings) and determine best output (longevity) for the IC40. I read all the pump vs output threads and articles and just want to have the best approach.

I know I will make adjustments throughout the summer, but, I’m very prepared to do so.

Thanks!
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
23,546
Bedford, TX
C,


The best approach for me is to try to maintain my Target FC or higher.. I never try to keep my FC between my minimum and my target.. If you do, it will drive you crazy.. A cloudy day will drive your FC up so you turn down the SWCG output, next day is sunny as all get out and your FC will drop too low, so you have to turn up the SWCG output. I never worry about going too high.. It just takes all the stress out of the equation.

Pump speed is whatever RPM turns on your flow switch plus 100 or 200 RPM.. If your pool skims at the speed you are done.

I run mine 24/7 at 1200 RPM most of the time, but have no heater. I can do that for less than $20 bucks a month.. I have two rent house that I do the same way.. I just had to replace two IC40 cells.. one was almost 9 years old and the other over 7 years old..

Thanks

Jim R.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
23,546
Bedford, TX
C,

If you think that 20% is what you need, then I would start at 40% and then work your way down..

In the perfect world, you'd set the SWCG to 20% and everything would be perfect.. But, a lot depends on your location, the amount of sun the pool sees, bather load, CYA level, etc.. Better safe than sorry.

What is your CYA level? The lower your CYA the more FC your pool will use..

Thanks,

Jim R.
 

Candurin

Well-known member
Jun 30, 2017
301
South Jersey
Pool Size
13000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Jim,

Just tested this morning. Here’s what I’ve got:

Temp = 61
pH = 7.5 (ish)
CL = 5 (ish)
FC = 5
CH = 300
TA = 40
CYA = 80 (just added yesterday, so might drop).

At these levels I may add a small amount of LC and then add the salt in tomorrow

We get 10 hours of sunlight per day over the pool.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
23,546
Bedford, TX
C,

When you initially add a large amount of salt the cell should be off for 24 hours.. This allows the salt to completely dissolve and won't cause the cell to report a high salt failure.

With a CYA of 80 your target is 6 ppm.

For some reason I thought your pool was bigger than 13K.. :scratch:

20% would increase your FC by about 2.6 ppm per day.. Based upon your location and CYA I suggest that you start at 30% and then work down from there.

I'd test your FC each day for a week at about the same time.. It won't take a day or so before you will start to get a feel for how much FC your pool uses. Once you get a feel for it, you can cut back your testing to once a week or less..

There is just no need to test CL if you are testing your FC..

Thanks,

Jim R.
 

Candurin

Well-known member
Jun 30, 2017
301
South Jersey
Pool Size
13000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
I know. I’ve been playing with the test kit and teaching my son how to do all the tests. In theory, I’ll start traveling for work again soon.

So we’ve been conducting all the tests :)

@Jimrahbe Should I go ahead and add salt today?

Pool math calls for 392lbs of salt. I was going to add 8 bags and see what that looks like. I’ll keep the IC40 output set to 0% for 24 hours (it’s been at that setpoint since day 1).
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
23,546
Bedford, TX
C,

I see no reason not to add the salt..

You need to know what the current salt level is before adding any additional salt.. I always suggest adding less than you think you will need, and then testing to see where you are..

I run my salt level at the lower end of the range.. Once it gets up to 3500 or higher, I can start to taste it.

Thanks,

Jim R.
 

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Candurin

Well-known member
Jun 30, 2017
301
South Jersey
Pool Size
13000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
C,

I see no reason not to add the salt..

You need to know what the current salt level is before adding any additional salt.. I always suggest adding less than you think you will need, and then testing to see where you are..

I run my salt level at the lower end of the range.. Once it gets up to 3500 or higher, I can start to taste it.

Thanks,

Jim R.
That’s an easy one, Jim. Salt level is 0. This was a new install as of November and is was winterized in December. Never added any salt as of today.

I ran a salt test last week (just to familiarize myself), the day I opened it, and was pretty much 0. It may have been 200 as I did get a very slight reaction after a drop.

I’ll put 200 ppm into the calculator and bring the salt to 3000 ish.

I’ll get my brush ready to start stirring. I wanted to use the robot to stir things up, but, it may suck up salt crystals and be wading through high ppm water. I’m sure it’s fine, but didn’t want to risk corroding anything in my week-old robot. It’s also too cold to throw our kids in :)

Last question (for today) @Jimrahbe. I’m making up numbers here. If I add 8 bags and get to 2800ppm, can I turn on SWCG? If I need to adjust/increase by a bag or two can the SWCG be running or do I need to shut it down anytime I add ANY amount of salt? Wasn’t sure if minor additions of salt while operating the salt cell is ok?
 
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