What kind of filter is it? If it is a gravity filter or skippy type you can leave it alone longer if it is a cannister type you have to clean those more because they can clog. One way to keep the beneficial bacteria and still clean your filter is to use pond water instead of the hose. I do this for my aquariums and it keeps from killing off all the good stuff.

Sometimes on my pond filters too I would do a quick clean and drain it and squirt it out but leave other media or mats untouched. You could spray some media and leave some unwashed so you always have some bacteria going.

Generally you don't want to use city water in the filter as it is a bacteria killer.

I clean my filters out 2-3 times a week as necessary, otherwise they clog and don't pass water. However, my filter is in several stages, and only the top layer catches muck, and its only the top filter I clean.

I keep two top filters going. I swap filters, spray the dirty one down with a hose and let it sit till the other filter needs cleaning. That way any chlorine can dissipate outside the filter.

Maybe I used the wrong word saying "filter". I mean the bucket with the filter medium, which in our case is lava rock and a pad. We have well water so chlorine isn't an issue.

So does the pad trap muck before it gets to the rock?

That can be cleaned off frequently. Try to leave the rock alone as that's where most of your bacteria is living. But even there, most of it will survive a rinsing off in well water.

When it stops pumping water! Mine is still going strong about 5 or 6 years ago I took all the media out and cleaned it- what a job. If the Bottom intake network clogs I'll backfill the pond. We paid a lot of attention to it the first 5 years or so, now seldom - but those little feeder goldfish are now 8" and bigger and there are new ones every year. I kept good records of the tests for a few years but nothing changed so haven't tested also in years. Sometimes in the summer water evaporates and we add some - winter rain keeps it full.

It could be a joy but for the damm Raccoons that tear up the plants.

You can clean the pad out as often as it gets gunky. Try to be very gentle with the lava rock so not to remove the good bacteria. Have you thought of using a different bio-filter media such as Savio Springflow under your pads? If you place it in large mesh bags you can just knock the gunk off without a need to rinse it. It does better laying loose in the filter but that is not practical for my uses. Some people use kitchen scrubbies too.