A filter arrangement for an aquarium is disclosed. The filter arrangement can include a housing assembly, a pump assembly, a transfer tube assembly, and a valve assembly for controlling water flow through the transfer tube assembly. The transfer tube assembly can include a tube structure within which a valve body of the valve assembly is rotatably disposed. The tube structure can be formed from a first tube half mated to a second tube half to permanently secure the valve body within the tube structure. A valve operator can be connected to the valve body to advantageously allow a user to manipulate the flow of water through the transfer tube assembly. Control of water flow through the filter arrangement is beneficial for obtaining a desired water flow for a certain aquarium size and application and for reducing flow during certain periods, such as during feeding.