A self-contained filtration assembly, comprising: a shell having a top portion, a bottom portion, an inlet connection and an outlet connection; at least one filtration cassette disposed between the top portion of the shell and the bottom portion of the shell; where the at least one filtration cassette includes one or more filtrate channel spacers, each of the one or more filtrate channel spacers defining an open interior volume bounded by an inner perimeter and including at least one feed port and at least one filtrate port, where the inner perimeter is shaped to reduce non-uniformities in a filtrate flow through the filtrate channel spacer, wherein the inner perimeter of the filtrate channel spacer defines a filtrate channel one or more feed channel spacers, each of the one or more feed channel spacers defining an open interior volume bounded by an inner perimeter and including at least one feed port and at least one filtrate port, where the inner perimeter is shaped to reduce non-uniformities in a feed flow through the feed channel spacer, wherein the inner perimeter of the feed channel spacer defines a feed channel, one or more membranes, the one or more membranes disposed between the one or more filtrate channel spacers and the one or more feed channel spacers, where the one or more filtrate channel spacers and the one or more feed channel spacers are arranged such that the feed ports and the filtrate ports are positioned in respective alignment, and a thin film of adhesive applied in a thickness of less than 50% the height of the adjacent channel, where the thin film of adhesive binds together the one or more filtrate channel spacers, the one or more feed channel spacers, and the one or more membranes; where the inlet connection directs a feed flow into the at least one filtration cassette; the outlet connection directs a filtrate flow out of the at least one filtration cassette; and the shell and the at least one filtration cassette are bonded together about the periphery. a shell having a top portion, a bottom portion, an inlet connection and an outlet connection; at least one filtration cassette disposed between the top portion of the shell and the bottom portion of the shell; where the at least one filtration cassette includes one or more filtrate channel spacers, each of the one or more filtrate channel spacers defining an open interior volume bounded by an inner perimeter and including at least one feed port and at least one filtrate port, where the inner perimeter is shaped to reduce non-uniformities in a filtrate flow through the filtrate channel spacer, wherein the inner perimeter of the filtrate channel spacer defines a filtrate channel one or more feed channel spacers, each of the one or more feed channel spacers defining an open interior volume bounded by an inner perimeter and including at least one feed port and at least one filtrate port, where the inner perimeter is shaped to reduce non-uniformities in a feed flow through the feed channel spacer, wherein the inner perimeter of the feed channel spacer defines a feed channel, one or more membranes, the one or more membranes disposed between the one or more filtrate channel spacers and the one or more feed channel spacers, where the one or more filtrate channel spacers and the one or more feed channel spacers are arranged such that the feed ports and the filtrate ports are positioned in respective alignment, and a thin film of adhesive applied in a thickness of less than 50% the height of the adjacent channel, where the thin film of adhesive binds together the one or more filtrate channel spacers, the one or more feed channel spacers, and the one or more membranes; one or more filtrate channel spacers, each of the one or more filtrate channel spacers defining an open interior volume bounded by an inner perimeter and including at least one feed port and at least one filtrate port, where the inner perimeter is shaped to reduce non-uniformities in a filtrate flow through the filtrate channel spacer, wherein the inner perimeter of the filtrate channel spacer defines a filtrate channel one or more feed channel spacers, each of the one or more feed channel spacers defining an open interior volume bounded by an inner perimeter and including at least one feed port and at least one filtrate port, where the inner perimeter is shaped to reduce non-uniformities in a feed flow through the feed channel spacer, wherein the inner perimeter of the feed channel spacer defines a feed channel, one or more membranes, the one or more membranes disposed between the one or more filtrate channel spacers and the one or more feed channel spacers, where the one or more filtrate channel spacers and the one or more feed channel spacers are arranged such that the feed ports and the filtrate ports are positioned in respective alignment, and a thin film of adhesive applied in a thickness of less than 50% the height of the adjacent channel, where the thin film of adhesive binds together the one or more filtrate channel spacers, the one or more feed channel spacers, and the one or more membranes; where the inlet connection directs a feed flow into the at least one filtration cassette; the outlet connection directs a filtrate flow out of the at least one filtration cassette; and the shell and the at least one filtration cassette are bonded together about the periphery.