Selecting the right size Intellichlor


LifeTime Supporter
We are about to start construction of a pool about 27000 gallons near Houston. We really want to go with SWG but I am unsure about the size. I guess we would go either IC40 or IC60. If we select the bigger one, will it be too much if we run the pump many hours (low flow rates)?

I generally prefer to get the right (large) equipment up front to minimize maintenance and problems down the road.

Any insight is welcome.


Well-known member
Oct 31, 2010
Deep South
I've tested successfully IC40 at 15 GPM (~ 1200-1250 RPM) on IntelliFlow VF and the Flow Switch activates chlorine generation.


Well-known member
Oct 4, 2010
Be careful with the lower flow rates. The safety of your family, including the cute little dog, are of primary importance. :)

Pentair cautions against a flow rate less than 25.

" WARNING - Never operate the IntelliChlor Electronic Chlorine Generator
(IECG) without proper flow or water circulation. A build-up of
flammable gases will result in hazardous conditions.
Operate unit with minimum flow of 25 gpm"


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Most of the time it is more cost effective to get a cell larger than what you really need. Cell lifetime scales with the size given that both are used on the same sized pool. So the IC60 will last 50% longer than the IC40, and doesn't cost 50% more, so you save money in the long run. A larger cell can also be handy when you need to raise the FC level quickly.

However, with the Pentair units in particular, when used without an automation system, there can be disadvantages to this. With an automation system the larger unit is well worth it. The issue without an automation system centers around how finely you can adjust the SWG percentage. An oversized unit needs to be run on a fairly low percentage to begin with, so you need fairly fine control to get the level you want. Without an automation system the Pentair SWG are set in steps of 20%, which can be too coarse for an oversized unit. The automation system lets you set it in steps of 1%, which works much more easily.


Well-known member
Dec 3, 2009
Central Massachusetts
Having the Pentair system myself, Jason is right on with his advice. If you are going to get the pentair automation, I'd do an IC-60. Without the automation, you will have difficulty fine tuning one that large. Get the IC-40 if you're not getting the automation. I have an IC-40 on a 14,000 gallon pool and w/o the automation i coudnt fine tune it very well.


Bronze Supporter
Sep 5, 2016
Glad I found this thread. Doing a 22K gallon pool with EasyTouch and ScreenLogic. Found this before PB ordered equipment. Asked them to upgrade from IC40 to IC60 for slight upgrade cost.

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