I'd been running it all week gutted on the floor and using an ice cream bucket as a reservoir while I finished the real res, and the temps posted are it!
At start up it's room temp, and drops to 14.5 within a minute. After about 5 hours it gradually "climbs" to 15. I've seen it hit 15.5 once while running Prime, but after an hour water temp went back to 15 and stayed there over night.
The tube that goes through the box from the underground loop to the waterblock has a 4" piece of copper tubing joining the two types of tubing, and on that is my temp probe fastened with furon temp conducting tape--the same tape the probes come wrapped in.
The system is res>pump>underground>CPU>back to res, so that's the temp from the ground.
I'm thinking of picking up a can of flat black BBQ paint to paint the drain fitting, so I can use an IR thermometer for a second opinion though...it's very thermally conductive paint, and the IR's are best on non shiny surfaces.
View attachment 109533
It says CPU, but I don't have a 7' probe to reach the CPU, the Aerogate complains when there's no probe or fan on the CPU channel, so I had to use one. Normally I don't care much about the water temp, but this is a bit of a special case I guess. The RPM is the 355. I plugged in both pumps and the fan to the controller so I get an alarm when something quits.