S19 Hydro Temp Management Issues

I can't seem to maintain the temp between 20 and 40 degrees. I’ve got a heater to raise the temp, but then it gets too hot. When I switch on the fans, it gets too cold. Don't these things come with an automatic thermostat? Am I really expected to be here constantly tweaking the fans?

wind cooling is stable than water cooling

Something like this might help you https://www.alibaba.com/product-detail/M1-S19-Hydro-Water-Cooling-System_1601123045309.html If it is expensive, you can easily design an automatic control circuit or buy a controller like this.

.... No they do not each have a thermostat and frankly do not need one as their temp is set by the water cooling loop so you just control the temp of the water. That ensures that all the miners run the same temp and makes for a much simpler/lower cost system. I assume you have a radiator w/fan so just connect a thermostat to the system to turn fans on/off (and turn the heater off) at the desired temps. It ain't rocket science...