I could either see building a acrylic box that was perforated which would probably look the best and keep the flow at the highest possible or wrapping the pump with either a course plastic window screen or the plastic screen used for needlepoint (I don't knit or sew so I am not 100% sure what it is called or used for, but it is a course plastic mesh that is used as a support for various projects, a hobby or sewing store might have it). The wrapping of mesh won't look so nice and will likely impede flow.