My Spa currently has 60hz 220v Service from a 50Amp GFCI shutoff (2 Hot plus Ground, Neutral terminates at the shutoff). I want to add a PH Control system to it that uses a probe to test the PH and has a receptacle to lug a solenoid in for a CO2 Tank. The system is rated for 60hz 110v and/or 50hz 220v. Assuming the Neutral in the PH system is not joined to the ground, would it work to use the 220v from my Spa's Ozone circuit and then wire in a 220v solenoid to the receptacle. If not, could I run a neutral from the GFCI shutoff and tap one leg of the Ozone Circuit with the Neutral to get 110v. I removed the Ozonator so that circuit is presently not being used.