filter location

[MarkP]

FWIW I selected a filter for the suction that had the largest and least restrictive rating that I could find. Locally that means 30 microns. I could probably get 50 microns if I ordered online. Let's not get hung up on terminology. I have a very fine strainer (30 microns) on the pump suction floating in my tank. After the pump but before the expansion tank I have a very, very fine filter (0.1 microns) that is supposed to filter out everything except viruses.