sense and dispense changing ORP & control of SWG


New member
Feb 2, 2018
I am new to owning a pool and this forum. I'm learning how to be our pool girl. I have a background in Chemistry, but this is all new.

I like automation, so I had the Hayward sense and dispense installed with omnilogic. We finally turned on our SWG T-15 and are having problems with a lot of ORP values changing. We have had no support from our pool builder (Pool Pro Maui) he just dumped in salt, and left and said to plug in the next day and call a pool maintenance company.

I researched ORP and understand it needs to be 650mv, and the FC levels should be 1-3ppm. First try at SWG ORP of 650mv, my FC was >10ppm so called them back, and complained it isn't working and he came and dumped in CYA to 80ppm. raised salt to 3600ppm said to wait for the Chlorine to burn off. I had a biz trip and when I came back, I had green algae on my tile steps and no chlorine left. I shocked it, brushed off algae, and then have been following the chlorine and ORP values.

My ORP has been around 600mv but last night, my ORP went to 290mv all of a sudden. I just turned it off and went to bed. Now it is back to 600mv, but that freaked me out.

ORP is now 600mv with FC 3ppm. PH 7.5 CYA 80ppm

I have set the ORP set point to 585mv. I am afraid to over chlorinate the pool again. Can someone give advice how to use ORP for the SWG? I think when the SWG gets turned on even at 585 it may over chlorinate.



New member
Feb 2, 2018
Thank you for the reply. It was my pool builder who dumped it in telling me it won’t work without it :)

what should I do now that I have cya 80ppm and a SWG cell and sense and dispense? Will Hayward help ?


Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
Tucson, AZ
:wave: Welcome to TFP!!!

You need the CYA to protect the FC from the sun. But, it also messes with the ORP (which is why we do not typically recommend them in outdoor pools, especially with SWG).
Best bet is abandon the ORP sensor and just operate the SWG in normal timer, % output mode.


Well-known member
Apr 15, 2018
Re: sense and dispense changing ORP & control of SWG

With the caveat/adder of the word OUTDOOR, I agree with the last post.

ORP and no CYA can work fine on indoor pools.