Minimum speed for my IC60 to generate chlorine

[joninnj]

I recently got a variable speed pump and found that a minimum speed of 1750 RPM was necessary to generate chlorine. So I set the pump at 1850 to run 24/7 (besides a few hours at higher speed to skim).

Today, I went out and tested the pool, and my FC/TC was zero! Turns out that the flow was too low for the IC60 to run. I did some more testing and found that the minimum speed for the IC60 to generate chlorine was now 1950-2000 RPM! I realized that the pump skimmer basket was a little full, cleaned it out, and the minimum speed dropped to 1850. So my new 24/7 speed, to ensure adequate margin, is 2200 RPM.

Question:
1. Is it unusual to have such a high minimum speed for the IC60 to work? Everything else about my pool has been and is running perfectly, clear water, balanced chemistry, etc. I have 3 returns, 2 skimmers, and a bottom drain.
2. Is 2200 RPM a reasonable speed to set? Should I run it higher? Lower? I am a bit spooked by having zero chlorine in the pool, and it seems that flow at lower speeds is much more impacted by some debris in the pump skimmer basket, which is why I have it set ~200 RPM above the highest minimum RPM to generate chlorine. Does this thinking make sense?

 

[HermanTX]

There are several items to check.
What is the % output for your SWCG? It is stated the pump was running continuous 24 hrs - correct?

When you tested initially the pump speed, was the green flow light on at 1750rpm? Did the flow light go out if the speed was less?

 

[PoolStored]

You need to clean your Filter. You also should run 200rpm above minimum to give you some protection from the filter being dirty.

Set speed 200 above swcg off. Clean your filter when pressure rises 25% above clean pressure and this should not happen.

Also, you need to test SWCG switch off RPM with a clean filter.

 

[ajw22]

You cannot compare the RPMs you hear discussed among folks who have 3+ HP pumps and your smaller Superflo pump. You will need more RPM for the equivalent flow.

Pentair has the AUTOMATIC BY-PASS VALVE KIT (P/N 462048) FOR MASTERTEMP® AND MAX-E-THERM® POOL AND SPA HEATERS. Install that and plug it into your IntelliCenter. Bypassing your heater when it is off will increase your flow rate so your IC60 will run with about 400 rpm less.

 

[joninnj]

There are several items to check.
What is the % output for your SWCG? It is stated the pump was running continuous 24 hrs - correct?

When you tested initially the pump speed, was the green flow light on at 1750rpm? Did the flow light go out if the speed was less?

SWG at 40%. Chlorine levels were rock solid with pump running at 1850 RPM 24/7. The initial 1750 RPM minimum speed and all subsequent minimum speeds determined by the green/red light on the IC60 while calibrating speed up and down.

You need to clean your Filter. You also should run 200rpm above minimum to give you some protection from the filter being dirty.

Set speed 200 above swcg off. Clean your filter when pressure rises 25% above clean pressure and this should not happen.

Also, you need to test SWCG switch off RPM with a clean filter.

Yeah, cannot hurt to clean filter, but my filter pressure has been stable since pool opening. Will re-test minimum speed for chlorine generation after cleaning filter.

AUTOMATIC BY-PASS VALVE KIT (P/N 462048) FOR MASTERTEMP® AND MAX-E-THERM® POOL AND SPA HEATERS

Not a bad idea, but I am a bit tapped out with all my recent upgrades (IntelliCenter and new heater last year, new liner and pump this year)!

 

[PoolStored]

filter pressure has been stable since pool opening

So, here is the thing. Pressure will not rise when running lower speeds. You need to check filter pressure at higher speed.

Pick a speed. 3000rpm. Always look at clean and dirty pressure at 3000rpm.

 

[joninnj]

So, here is the thing. Pressure will not rise when running lower speeds. You need to check filter pressure at higher speed.

Pick a speed. 3000rpm. Always look at clean and dirty pressure at 3000rpm.

Ahh, that makes sense. Never thought of that.

 

[HermanTX]

SWG at 40%. Chlorine levels were rock solid with pump running at 1850 RPM 24/7. The initial 1750 RPM minimum speed and all subsequent minimum speeds determined by the green/red light on the IC50 while calibrating speed up and down.

For reference data - 27k.gal pool, set at 40% and 24 pump runtime for IC60 will produce 3.6ppm per day. With the heat wave, you may be consuming that as well. So you are on the edge.

 

[joninnj]

For reference data - 27k.gal pool, set at 40% and 24 pump runtime for IC60 will produce 3.6ppm per day. With the heat wave, you may be consuming that as well. So you are on the edge.

Thanks. You bring up something I’ve observed: heat increases consumption. But it seems that the dogma here is that it’s sunlight, not heat. Granted, they’re often correlated, but is more chlorine consumed on sunny days in the 90s vs. sunny days in the 70s?

 

[PoolStored]

is more chlorine consumed on sunny days in the 90s vs. sunny days in the 70s?

Yes.