Without long details:
Holding tank was pressurizing.
Looked up inside vent on the hullside, appeared clogged. Also kink in the hose on vent backside.
Replaced vent, relieved hose.
Still pressurizing.
Removed vent hose from tank. Oops, it was full. (#1)
I check it with a flashlight but apparently the line was a false one from previous contents.
Realized that pump outs had not been complete recently, due to clogged vent. Therefore drastically miscalculated capacity.
The old 2 burnt light bulbs in the Christmas tree syndrome: Clogged vent = bad pump outs. Bad pump outs = clogged vent (at tank).
Holding tank was pressurizing.
Looked up inside vent on the hullside, appeared clogged. Also kink in the hose on vent backside.
Replaced vent, relieved hose.
Still pressurizing.
Removed vent hose from tank. Oops, it was full. (#1)
I check it with a flashlight but apparently the line was a false one from previous contents.
Realized that pump outs had not been complete recently, due to clogged vent. Therefore drastically miscalculated capacity.
The old 2 burnt light bulbs in the Christmas tree syndrome: Clogged vent = bad pump outs. Bad pump outs = clogged vent (at tank).