Help with IntelliChem settings

RAH123

Member
Apr 8, 2021
5
poway, ca
Hi I have an intellichem, pool cover, and the SWG. I've been having trouble figuring out the best intellichem settings for my SWG. It appears even though I tell it low sensitivity for the ORP it still goes 100% and , for some reason, when the SWG is on, it drives my ORP lower for hours. When I set my ORP setting to low enough that the SWG is off, then the ORP starts rising. Not sure what could cause that (bad install or something I dunno?). But With pool cover closed, and SWG IC40 running with ORP setpoint of 700 it will go all the way down to 650 then skyrocket up later in the day to 750 or 800. CYA is around 18. No combined chlorine/chloramines, all FC for the most part. I'm thinking it may be good for it to dose the SWG for a few hours, then wait and see the reading before dosing some more. One pentair guy told me that IC40 is way too powerful for my little 14k gallon pool. I'm tempted to write some software to communicate to it directly and control it, but not sure where the API's or documentation might be on how to control the system over web/TCP/HTTP Get etc.
 
I have the exact same equipment and response. Turning on the IC-40 drives ORP lower. If the IC-40 has been off for more than 24 hours, it REALLY drops (like 150mV in a couple of hours. If the IC-40 remains on, then over a few days the ORP will stabilize into a diurnal rhythm as the sun comes up and goes down. I've narrowed this down to two possibilities I think:

1) The hydrogen gas generated in the IC-40 is enough to lower ORP. This is my current favorite theory. H2 is very negative ORP and even a little bit has a big impact. I believe this to be true because if I run my waterfall (and thus all return water is falling over the water fall), while the IC-40 is on, ORP will begin to rise, even though pH also rises. I believe the H2 is outgassed more quickly going through the waterfall. I wish there was a way to liberate the H2 when I'm running low pump speed just skimming.

2) Some electrical interference caused by the IC-40. This theory has fallen out of favor because I would expect this kind of interference to be more immediate than I see.

I do wish the ORP dosing protocol was more proportional instead of a bang-bang type of system. I've had to set the ORP dosing on the intellichem to time and run the IC-40 10 minutes on/5 minutes off to make dosing more manageable. I am currently running a 750 ORP setpoint and typically this is reached sometime in the night and the ORP will rise with the IC-40 off to about 770-800 until the sun comes out and drives it back down below 750. My mid-day FC tests out at about 3.4ppm. I'm running <20 CYA but not sure exactly where I'm at (guessing 5). ORP is not a proxy for FC, but its all we have to work with on the intellichem. Most people will tell you its unusable but it can work if you keep CYA low and dose ORP by time rather then to a setpoint.

I'm currently trying to figure out if adding borates will somehow effect the chemistry in a way that will reduce the H2 impact on the ORP. I know it gobbles up OH- but I'm not sure that will help. It should prevent such a large pH increase inside the cell, but I'm not a good enough chemist to understand if that would disfavor H2 production in anyway.
 
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I have the exact same equipment and response. Turning on the IC-40 drives ORP lower. If the IC-40 has been off for more than 24 hours, it REALLY drops (like 150mV in a couple of hours. If the IC-40 remains on, then over a few days the ORP will stabilize into a diurnal rhythm as the sun comes up and goes down. I've narrowed this down to two possibilities I think:

1) The hydrogen gas generated in the IC-40 is enough to lower ORP. This is my current favorite theory. H2 is very negative ORP and even a little bit has a big impact. I believe this to be true because if I run my waterfall (and thus all return water is falling over the water fall), while the IC-40 is on, ORP will begin to rise, even though pH also rises. I believe the H2 is outgassed more quickly going through the waterfall. I wish there was a way to liberate the H2 when I'm running low pump speed just skimming.

2) Some electrical interference caused by the IC-40. This theory has fallen out of favor because I would expect this kind of interference to be more immediate than I see.

I do wish the ORP dosing protocol was more proportional instead of a bang-bang type of system. I've had to set the ORP dosing on the intellichem to time and run the IC-40 10 minutes on/5 minutes off to make dosing more manageable. I am currently running a 750 ORP setpoint and typically this is reached sometime in the night and the ORP will rise with the IC-40 off to about 770-800 until the sun comes out and drives it back down below 750. My mid-day FC tests out at about 3.4ppm. I'm running <20 CYA but not sure exactly where I'm at (guessing 5). ORP is not a proxy for FC, but its all we have to work with on the intellichem. Most people will tell you its unusable but it can work if you keep CYA low and dose ORP by time rather then to a setpoint.

I'm currently trying to figure out if adding borates will somehow effect the chemistry in a way that will reduce the H2 impact on the ORP. I know it gobbles up OH- but I'm not sure that will help. It should prevent such a large pH increase inside the cell, but I'm not a good enough chemist to understand if that would disfavor H2 production in anyway.
Can you tell me the setting you use for 10 on and 5 min off? I can’t get the intelichem to turn my IC40 off.
 
Can you tell me the setting you use for 10 on and 5 min off? I can’t get the intelichem to turn my IC40 off.
On the intellichem front panel go into orp menu ->orp dosage 1/2 and change to dose by time. Set the mixing time to the off time you want. Go to page 2/2 set the dosage time to the time you want on.

I think that’s close to accurate going from memory.
 
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On the intellichem front panel go into orp menu ->orp dosage 1/2 and change to dose by time. Set the mixing time to the off time you want. Go to page 2/2 set the dosage time to the time you want on.

I think that’s close to accurate going from memory.
Thank you! This seems to have solved the problem.
 
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i contacted pentair tech support many times until someone explained it where it made sense. They said with a pool cover and ORP we may be running into ORP suppression. The chloramine gasses from bound up chlorine can't escape due to the cover and then get back into the pool, and then the chloramines drive ORP down. I've set my dosing to timed, and am doing 20 minutes dosing and 60 minutes mixing time (off) and that seems to work quite well when the cover is on, but when the cover is off and in the hot sun i'm not sure if it will dose fast enough, we'll see. Before I set it to this, I was unable with the cover on to keep it within 650 to 750 orp, it would fall outside that range and spike to almost 800. Now i'm able to keep it in 675 to 725 range usually. I also have another system that does AOP and is called Clear Comfort. It has a UV bulb and somehow injects hydroxyl radicals that oxidize things it comes into contact with (no residual) and although that system should run 23 hours a day i have it running 10 hours a day with chlorine, it may be helping to break down the chloramines but not fast enough so that's why the mixing time off. I may have to reduce the mixing time off to a lower value, or change the dosing to less, and then scale down the mixing as well. One thing I found has helped a bit also, once the pumps start up in the morning, the ORP starts rising without any additional chlorine. So I've set my power on delay for my ORP system to 1 hour. That way it won't try and do any dosing until the pump has been running at least an hour and stabilizes. Of course in that 1 hour my clear comfort has been doing some work, so i'm not sure how applicable this is to you. I did have the ORP delay of 1 hour for power and 1 hour for flow, and they do add up to 2 hours. That worked even better for me, but my pool guy is worried those flow sensors sometimes trip and you don't want your 1 hour flow sensor to keep your dosing offline all day with flaky flow sensor output. I do have the ability to write software, so we may just use wireshark or something to watch the tcp/ip packets and determine the protocol then come up with a small board the automates this better. Alternatively we may be able to use a relay to control the SWG with the app and a duty cycle but we haven't dove into that much.
 
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