Unreliable DS18B20 Readings

[pwest]

Hi:
I recently set up a robo-tank with this configuration:

• Reef-pi Deluxe Aquarium Controller Fully Assembled
  
• 'pi zero w
  
• the recommended Alarmpore Power Adapter from Amazon 
  
• one 0-10V LED channel driving Mean Well ELN-60-48P supplies (my white LEDs)
  
• another 0-10V LED channel driving Mean Well ELN-60-48P supplies (my royal blue LEDs)
  
• one DC channel driving a return pump via a Digital Loggers, inc IoT relay     
  
• a second DC channel driving a return pump via another Digital Loggers, inc IoT relay
  
• One DS18B20 1-WIRE Waterproof Digital Temperature Sensor Probe - 3 meter cable  in the display tank, one sample per minute
  
• A second DS18B20 1-WIRE Waterproof Digital Temperature Sensor Probe - 3 meter cable measuring ambient temperature, one sample per minute
  

With the system assembled, configured and running upstairs in my office, the temp sensors seemed to be working reliably and the pump and lighting controls behaved as programmed/expected.  When I moved everything into the fish tank room and hooked it up, the temp sensors became unreliable.  Specifically, after a variable and inconsistent amount of run time (sometimes many hours, sometimes only a few minutes), they will begin to read some small negative value, and produce an error like:
temperature sub-system. Failed to read sensor RoomTemp. Error:open /sys/bus/w1/devices/28-3c01d075740d/w1_slave: no such file or directory
occasionally, the system will recover from this and begin to produce accurate readings, but that's more the exception than the rule.  Powering down the entire system, including removing the supply power from the Robo Tank and waiting a couple of minutes will restore correct operations upon reboot.

Evidently, this is a know issue w/raspberries, and is discussed in this thread:
https://www.raspberrypi.org/forums/viewt...p?t=164059

To begin to diagnose/resolve this issue, I have established that two of the conjectures/issues thought to exacerbate the problem are not central to my case.  In the cited thread, it is suggested that long sensor leads are problematic, and that some counterfeit 'Chinese' DS18B20 parts are inferior.  I had a couple of DS18B20 samples that were shipped directly to me from Maxim, so I screwed one of those directly into one of the green plastic couplers, and the problem persists.

Any thoughts about how to debug/diagnose and resolve this issue would be appreciated!

Thanks for reading,
Phil