Abstract: Methods, devices and systems for treating liquid utilizing an in-line filter having a filter bag positioned within a cage contained in an exit sub-chamber of a housing, the exit sub-chamber isolated from an inlet sub-chamber by a baffle, and an end cap to alternatively seal the inlet sub-chamber so that in one mode the device may function as a screen having an exposed filter bag when the exit end of the device is connected to a suction side of a pump and in another mode as a closed vessel where the end cap is connected to a discharge of a pump or in a further mode where the exit end is connected to a suction side of a pump. The low profile, lightweight, inline filter device provides for versatility and a much needed filter device for two modes of connection to a suction side of a pump while also able to connect to a discharge side of a pump.