I have a new Ultitube100 Pro with a D5 Next hooked up to a new power supply with the jumper installed. No other cables are attached to the D5, just the sata power cable. I have two radiators in a test loop and nothing else. I am using the test loop with distilled water to flush the new radiators. Everything starts up fine but consistently after about 2-3 hours I start getting a "Pump Speed Too Slow" alarm. Stopping and restarting the power supply does not clear the error. When started it is runn...

FYI - Here is the answer I got from Aquacomputer support. (very fast response I might add - nice!) Thank you for contacting us! If your Ultitube came with a pre-installed D5 NEXT pump, it must be the "PRO" version of the Ultitube. All PRO version Ultitubes come with a pressure equalization membrane installed in the top lid of the reservoir, so will not hold pressure by design. If you want to pressure check your loop including the reservoir, you can try to put some plastic foil between glass tube...

I am building my first loop and decided to splurge on the Ultitube. After getting all the tubing routes designed and installed, I did a system leak test with air. After some research, it turns out the Ultitube is the only thing that is leaking air. I disconnected the tubes from the input and output ports, plugged the output port and attached the leak tester to the input port. The Ultitube will not hold air pressure indicating there is a leak somewhere. I checked all 3 seals: the d5 pump and the ...