Hey Andy, when you get this done post some pictures.. I was thinking about doing the same thing because I forget to check the level in my reservoir. I am using a 22 gallon Brut trash can for ATO reservoir, and am leery of drilling a hole. Would hate to have 20 gallons of water on the floor due to a leak behind my tank skin. Wanted something I can hook to my APEX to send an alert when the water level is low...