6 weeks is awhile....even tho the flow is still good. If you have been running your pump frequently, had a lot of debris/pollen/dust, etc., or vacumed, it can become pretty dirty. We have a cartridge filter, I would say we hose it off once a month (or more if the heater doesn't kick on it's usually from a dirty filter).
I would say, for fun, LOL, hose it off, and then make a note of your clean filter pressure....