A submersible pool cleaning device includes a device body having a filter canister mounted within the device body. A plurality of filter cassettes is releasably mounted within the filter canister, each filter cassette having a filter container and a flotation device. A cartridge is mounted to the device body configured to release a gas into one of the flotation devices to inflate the flotation device. A controller is configured to activate the cartridge to release the gas into the flotation device in response to detecting that the filter container is full and to release the filter cassette from the filter canister upon inflation of the flotation device. A method for removing the floating debris bag includes capturing and removing the floating cassette by a drone. A cassette collection method includes activating a pool skimmer pump and detecting that the cassette has reached the pool skimmer.