Pentair IntelliChlor IC20 vs. IC40: Which Salt Cell Does Your Pool Need?
If you're replacing a Pentair salt cell, the choice almost always comes down to two models. The IntelliChlor IC20 (part EC-520554) and the IntelliChlor IC40 (part 520555). They look nearly identical on the shelf, and both screw into the same plumbing, so people call us all the time asking which one to buy.
The short version: your pool size makes the decision for you, but if you're anywhere near the line, go bigger. We'll explain why below.
What's the difference between the IC20 and the IC40?
Capacity. That's really it. The IC20 is rated for pools up to 20,000 gallons and produces about 0.70 pounds of chlorine per day at full output. The IC40 is rated for pools up to 40,000 gallons and produces about 1.40 pounds per day, exactly double.
The housing, the unions, the cord, and the electronics all follow the same design. Both cells plug into the same IntelliChlor Power Center, and both work with Pentair automation systems like EasyTouch, IntelliTouch, and IntelliCenter when the salt chlorine generator option is set up. So this isn't a features comparison. It's a sizing question.
Which salt cell size do I need for my pool?
Match the cell to your actual pool volume, then round up. Here's the quick guide:
- Pool under 15,000 gallons: the IC20 (EC-520554) can handle it, though the IC40 still isn't a bad idea (more on that in a second).
- Pool between 15,000 and 20,000 gallons: this is the gray zone. The IC20 will work, but it'll be running hard. Most of our customers in this range are happier with the IC40.
- Pool over 20,000 gallons: the IC40 (520555) is your only real option of the two. An undersized cell in a big pool simply can't keep up, especially in July and August.
If you're not sure of your gallons, a rough formula for a rectangular pool is length x width x average depth x 7.5. A 16x32 pool with an average depth of 5 feet works out to about 19,200 gallons. Right in that gray zone, and a good example of a pool that should get the IC40.
Why buying bigger than you need saves money
A salt cell wears out based on how hard it runs, not how old it is. Every cell has a limited number of operating hours in it, and running at a high output percentage burns through those hours faster.
Put an IC20 on an 18,000 gallon pool and it might need to run at 80 to 100 percent output all summer just to keep up. Put an IC40 on that same pool and it can loaf along at 40 or 50 percent. Same chlorine in the water, way less wear on the cell. That usually translates to extra seasons of life before you're shopping for a replacement again.
Yes, the IC40 costs more up front. But if it lasts noticeably longer than an overworked IC20, the cost per year often ends up lower with the bigger cell.
Are the IC20 and IC40 compatible with the same system?
Yes. Both cells use the same cord and connector and mount in the same spot, so an IC40 is a direct swap for an IC20. If your old IC20 died and your pool is near or above its rating, this is the perfect time to upgrade to the 520555 instead of buying the same size again.
One thing to check: your power center needs to be in good shape too. If the cell light won't come on at all or the unit shows no power, the problem may be the power center or the board rather than the cell itself. Worth ruling out before you spend money on a new cell.
What does each cell cost to replace?
The IntelliChlor IC20 (EC-520554) runs $1,179 and the IntelliChlor IC40 (520555) runs $1,999. That gap looks big, but remember the IC40 gives you double the output and, on a mid-size pool, a much easier life. Spread over the extra seasons you're likely to get, the difference shrinks fast.
The bottom line
Small pool, tight budget, under 15,000 gallons: the IC20 (EC-520554) will serve you fine. Anything bigger, or anywhere close to 20,000 gallons, get the IC40 (520555). It runs at a lower output percentage, lasts longer, and keeps up when the water gets hot. Very few people regret buying the bigger cell. Plenty regret buying the smaller one.
Not sure this is the right part for your problem? Reach out and we will help you figure out exactly what you need before you spend money on the wrong thing.