Bought a fancy coffee grinder once and went back to my cheap one within days.

Tap water is the number one killer of moss and nobody wants to hear it. That chlorine and calcium builds up in the moss and there's no coming back from it once it crusts over. Distilled is fine but rainwater is free and the moss loves it. You probably didn't even need to move the tank, the water was doing most of the damage. Portland water isn't even that hard compared to a lot of places, so this would've happened to you anywhere.

Killed the main in 20 seconds? Thats the right call but 4 feet from the panel means that pipe was prob already running right next to where you had to drill, not really bad luck. Carry a couple sharkbite caps in 1/2 and 3/4, theyre cheap and save your ass.