Throw the strips away and get a decent test kit. With calicum at 350 you have a greater risk of the plates building up. Scaletec should help in addition to checking cell every 3 months.
Re: Infinity pool pump setup
You should be able to shut on off without continuous water loss. Sounds like a check vAlve needs to be installed or repaired.
Few things to check. When you turn on the heater from your remote does a red light turn on at the controller at the "heater" button. And as asked earlier is "bo" enabled and a light beside pool or spa at the heater.