Intellichem - and yup orp issue

dradam

LifeTime Supporter
Mar 10, 2013
213
Maryland
Pool Size
19000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
I have been running the intellichem for about 7 years now. My ph is muriatic acid, my chlorine is from the intellichlor. The ph is always consistent , but I have had to replace one probe and usually they need a gentle cleaning once in a while. The orp works well, but is sensitive to everything. CYA will decrease the orp readings. In your case I suspect pucks in the basket are what caused your sustained drop -- until they dissolved. Pucks in the basket are like washing your probes with cya and fc directly.
Opening the pool cover (I have a covered pool too) will drop the orp quickly during that time frame with any sun exposure.

To get consistent readings:

I run my pumps 24/7 but at 15gpm about 200 watts so the energy consumption is low. This is about 1 turnover per day for me. Water is always flowing
in the intellichem cell. With cover open or high bather load or cleaning i will increase the pump speed.
I maintain temp at about 86 degrees. Temp changes will affect the orp readings as well as salinity readings and the system fails as the fall/winter approaches.
My probes are on high sensitivity and dispense chlorine and MA with minimal variations.
I dilute my MA by 50% and dose 100 ml at a time with a short lockout.
I keep the cya less than 30. I find the cya really affects the orp readings
I keep fc slightly high about 5. Even a brief drop will make the water cloudy so I like a cushion.

Proactive:

If i will be leaving the pool open for a day or expect a high bather load I will increase the orp ahead. For kids pool parties I may keep some liquid chlorine around-- The SWCG may have trouble keeping up. ( my next one will be oversized (IC60)

Points of failure:
The probes can be bad and do fail- I have replaced each once so far in th 7 years.
My initial intellichem was defective- pentair replaced it and no problems since.
Oddly enough the probe cables can fail as well.I have replaced these on occasion ( maybe water gets inside when it rains ?)

I think from what I read here you are doing eveything right--- I think the trichlor pucks in your basket messed up you readings in that interval. I would add chemicals to the pool itself.
Wth this system you always have to adjust your baseline when any chages are made and correlate your orp reading to your FC level, but I have had full summers with minimal effort.

Hope this helps.
 

dw886

Gold Supporter
Sep 19, 2016
251
ND
I have been running the intellichem for about 7 years now. My ph is muriatic acid, my chlorine is from the intellichlor. The ph is always consistent , but I have had to replace one probe and usually they need a gentle cleaning once in a while. The orp works well, but is sensitive to everything. CYA will decrease the orp readings. In your case I suspect pucks in the basket are what caused your sustained drop -- until they dissolved. Pucks in the basket are like washing your probes with cya and fc directly.
Opening the pool cover (I have a covered pool too) will drop the orp quickly during that time frame with any sun exposure.

To get consistent readings:

I run my pumps 24/7 but at 15gpm about 200 watts so the energy consumption is low. This is about 1 turnover per day for me. Water is always flowing
in the intellichem cell. With cover open or high bather load or cleaning i will increase the pump speed.
I maintain temp at about 86 degrees. Temp changes will affect the orp readings as well as salinity readings and the system fails as the fall/winter approaches.
My probes are on high sensitivity and dispense chlorine and MA with minimal variations.
I dilute my MA by 50% and dose 100 ml at a time with a short lockout.
I keep the cya less than 30. I find the cya really affects the orp readings
I keep fc slightly high about 5. Even a brief drop will make the water cloudy so I like a cushion.

Proactive:

If i will be leaving the pool open for a day or expect a high bather load I will increase the orp ahead. For kids pool parties I may keep some liquid chlorine around-- The SWCG may have trouble keeping up. ( my next one will be oversized (IC60)

Points of failure:
The probes can be bad and do fail- I have replaced each once so far in th 7 years.
My initial intellichem was defective- pentair replaced it and no problems since.
Oddly enough the probe cables can fail as well.I have replaced these on occasion ( maybe water gets inside when it rains ?)

I think from what I read here you are doing eveything right--- I think the trichlor pucks in your basket messed up you readings in that interval. I would add chemicals to the pool itself.
Wth this system you always have to adjust your baseline when any chages are made and correlate your orp reading to your FC level, but I have had full summers with minimal effort.

Hope this helps.
dradam - thanks for chiming in. I log my additions too, and I've been adding trichlor pucks here and there since the start of my logging, and unforunately, the addition of the pucks doesn't seem to correlate at all with the pucks being in the skimmers (in fact, right now, I have a trichlor puck in each of 2 skimmers, and my ORP reading shows 699. I can definitely tell by pH when the pucks are in the skimmers however, as the pH is suppressed.

I also run my pump 24x7 at about 200 watts (enough to not get a low flow on my IntelliChlor SWG). My baseline right now is right at around 700 mV for ORP. Like I've said in the thread, it's consistent, but for some reason it swings. I have a brand new ORP sensor laying on the counter in the box, but I haven't installed it because I think 700mV is probably an accurate reading based on my FC. My CYA is < 30 ppm (somewhere just over 20ppm right now based on calculation from the trichlor pucks and the CYA test).

I'll continue to log. The tech from pentair is going to be in town for another intellichem system in the coming weeks, so I am going to try to talk through this with him as well.
 

jonpcar

Bronze Supporter
Jun 1, 2016
589
Gilbert, AZ
dradam , thanks for the input! Sounds like you consider it a success.

Temp changes will affect the orp readings as well as salinity readings and the system fails as the fall/winter approaches.
Regarding fall/winter...the ORP system fails? is this a short failure time before it recovers, or do you have to do something special to get it working again?

I keep the cya less than 30. I find the cya really affects the orp readings
What I’ve read about this seems to vary quite a bit. I’ve read some that say higher CYA levels just dampens/mutes the signals sent out by the ORP probe...there is not enough variation to do chlorine management. Others seem to indicate that the orp probe gives totally wrong information when higher levels of CYA are present. How do higher cya levels affect yours?

Thanks.
 

dradam

LifeTime Supporter
Mar 10, 2013
213
Maryland
Pool Size
19000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
In the fall I shut down the heat and the saline readings become innacurate. This causes the saturation index to be wrong so the whole system is less valuable to me when the water is cooler. I have found that higher levels of cya give me more variable readings. Adding cya at the beginning of the season seems to lower the orp readings. I keep a low cya for that reason. As a result fc drops quickly in my pool when the cover is open. For that reason I set my orp to a silghtly high chlorine fc level. My intelichem is about 5 years old, when it dies I will go from IC 40 to IC60. I think that will help keep the fc more stable with cover open.
 

dw886

Gold Supporter
Sep 19, 2016
251
ND
So a little more to add to this thread. Last week was the perfect storm. We were out of town, and 3 days after leaving, the ORP sensor decided that it was going on vacation too. It started reporting an insanely low level (the ORP mV reading was in the 100s and 200s, but the history on the ScreenLogic chart bottoms out at 300). This caused the Intellichem to dose via the SWG to the maximum daily limit, which was set to 10 hours in 30-minute intervals with 20 minute mix times. So on my IC60, it was dosing almost a pound of chlorine per day.

It did this for a little over 4 days. I came back to a FC level that was 18, and a system that was insistent on only driving it higher.

To stop it from dosing more, I set the Mix Time on the IntelliChem to 23H 30M, so it would only dose 1x per day. I got my new ORP probe installed last night, and things are coming back into line today.

This is basically what I've been alluding to all along. If the ORP probe goes nuts (which I've seen now multiple times), the pool chemistry goes wonky in an automated fashion, pulling you into trouble fast. I've had those happen with both low or high readings.

Here's what this looks like on the 30-day view:
112530

Here's a view of only the "problem" area last week of a 7-day view:
112531
 

jonpcar

Bronze Supporter
Jun 1, 2016
589
Gilbert, AZ
dw...thanks for the update. That sort of failing seems to occur in a number of ORP installs that I have seen. I am surprised that such a massive failure doesn't cause the firmware to undergo some kind of shutdown. Is there any way to generate alerts with the IntelliChem or does that require a more capable pool controller? How is the new probe working so far?
 
  • Like
Reactions: MyAZPool

dw886

Gold Supporter
Sep 19, 2016
251
ND
dw...thanks for the update. That sort of failing seems to occur in a number of ORP installs that I have seen. I am surprised that such a massive failure doesn't cause the firmware to undergo some kind of shutdown. Is there any way to generate alerts with the IntelliChem or does that require a more capable pool controller? How is the new probe working so far?
The new probe ORP seems to be closer to being in line with what I'd expect - it's measuring in the upper 600s and the mid 700s over the course of the last two weeks which is what it should read given my FC numbers.

There's no way to generate alerts with the Intellichem out of the box. It's pretty much reliant on watching Screenlogic and frequent testing.

My pH probe went wonky yesterday. The pH is about 7.5 right now (and has been for weeks). Yesterday it was reading 7.49, and then suddenly dropped to 6.9, and a few hours later came back to 7.5. I'm glad that it failed downwards and not upwards, because if it would have inadvertently reported 8.1, it would have been causing a dump of acid as it tried to correct itself...

113969
 
Thread Status
Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.