Roy G. Biv wrote:
Thanks for those insights Rich, I guess the key is how much the
different uM ratings load the pump and change its volume/time. I have
used different micron rated filters and never noticed a perceptible
change in the flow rate (5 gallons in 6.5 minute is pretty slow)...


There is a 'ratings game' with such filters. Firstly, 'paper' filter
media cant be made that accurately, plus the cellulose fibers used are
relatively thick in comparison to the 'pores'. So, in especially the
larger retention ratings you probably wont see much difference in flow
performance. With respect to cheap filters, you usually get what you pay
for.

:-)