All-in-one Pool Monitor & Controller

Hi all, looking for suggestions for hardware to control and monitor my pool system.

I need the following IO/control:

Pool pump control: 220v, 2 phase. Could be an external contactor coiled by low-voltage GPIO.
Pool/Spa Heater control: two independent, dry-contact or opto-isolated relays.
Temperature Sensor: Not sure where to mount this, but I like the idea of the 10k thermistors that clamp directly to the PVC pipe. (https://www.amazon.com/Hayward-GLX-PC-12-KIT-Thermistor-Temperature-Replacement/dp/B004RR90GM/ref=sr_1_1?dchild=1&keywords=10k+pool+thermistor&qid=1588966807&sr=8-1)
Pressure sensor: Not yet purchased, but I’m imagining something mounted to the 1/4" NPT insert on the filter. I’ve seen both 4-20mA and 0-10v variants on Amazon.

I was at first thinking of just using the Sonoff 4ch Pro R2 to do this and flash it to ESPHome, but see that the ESP8265 only has one ADC. I would also need to solder direct to the chip to expose that pin. I liked the Sonoff 4ch because it could be mounted easily onto DIN rail in a nice enclosure.

The other option seems to be an ESP32 based board in order to take advantage of the multiple ADC’s. The issue with this is that I’ll need to do some logic shifting to control external relays and will require some custom bread-boarding - the Sonoff 4ch has the relays I need already built in.

The other option might be to just use the Sonoff 4ch for the relay control and pressure sensor and purchase a Sonoff TH16 or similar with a ds18b20 probe and just have two controllers…

Thoughts? Is there a magic-bullet solution here, or is there some amount of compromise in any scenario?

NB: apart from ESPHome devices, I also have Insteon but no Z-wave in my system. I do also have an Arduino Uno and RPi spare lying around that could be utilized.

Thanks.

I’m going through some similar thoughts. Just bought a home with a pool. Currently my chlorinator and pump are working although not smart so will leave that for now.
I have purchased some ds18b20 temp probes in a thermowell. My plan is to put 2 in, one one pool return and one on the solar side. I will use a tee piece in 40mm pressure with a 20mm plug and will install the thermowell into that. Simply I can replace thermowell without making adjustments to the pvc.

I would love to have some external touch screen at the pool displaying pool temps, as well as have a control for the Spa blower, garden lights, pool lights etc but not sure yet on best way for this. Would prefer it to have its own intelligence so it can remain if I sold the house. Sonoff 4ch is on order as well.
Regarding smart sockets externally I’m in AU and wondering to simply go for a smart powerboard in a waterproof power junction box like this : https://www.bunnings.com.au/excalibur-6-outlet-outdoor-safety-box_p4360215

For the temp monitoring the plan was to wire both of these back to a ESP board - temps will only be for monitoring.