The problem with a submersible pump may be, if “unsupported “ would be the torque during a start. The pump will twist, pretty aggressively!
We’ve done similar using our (back-up) 12 volt RV water pump. We pulled from a clean mountain creek, discharged thru a filter, into a 55 gallon (food grade) plastic drum with Clorox (bleach) in drum. We left the bung open on the drum, and waited at least 24 hours four the water treatment to be effective, and to gas-off ( minimize the residual chlorine in water).
Probably frowned upon by many, probably “not” recommended, but,we didn’t die....at least not yet! :B
