Support and drainage material, filter, and method of use

A filter system comprising

• a pleated porous filter having a plurality of pleats and having an upstream surface and a downstream surface;
• and
• a support and drainage material system comprising
• a first support and drainage material and a second separate support and drainage material;
• (a) the first support and drainage material comprising
• (i) a section having a first end and a second end, and a first major surface, and a plurality of parallel tapered flow channels extending from the first end to the second end, the tapered flow channels comprising tapered side walls arranged in parallel and projecting upwardly from, and perpendicular to, the first major surface, the tapered flow channels having a deeper end and a shallower end, and being deeper at the first end of the section than at the second end of the section, wherein the tapered flow channels are connected at the first end with cross members, and connected at the second end with cross members;
• and
• (b) the separate second support and drainage material comprising
• (ii) a section having a first end and a second end, and a first major surface, and a plurality of parallel tapered flow channels extending from the first end to the second end, the tapered flow channels comprising tapered side walls arranged in parallel and projecting upwardly from, and perpendicular to, the first major surface, the tapered flow channels having a deeper end and a shallower end, and being deeper at the first end of the section than at the second end of the section, wherein the tapered flow channels are connected at the first end with a cross member, and connected at the second end with a cross member;
• wherein the pleated porous filter is arranged between the first support and drainage material and the separate second support and drainage material, and the first support and drainage material and the separate second support and drainage material are rotated 180 degrees with respect to each other.