I don't have bio critters as I use biocide regular every fill (I run 49 cetane, B2 fuel) and I've cleaned (new lower screen and fitted hose) and recheck sending unit twice. I have disassembled the sending unit to clean, reassembled the sending unit. I've never run it low enough I guess to have the fuel light come on, the most I've ever put in the tank is 16.3 gallons. I guess I'll start carrying a fuel can as it gets close to next fill time, and drive the thing till fuel light comes on or I run out or whichever occures first.
