When the pump / filter is in use in the pond, I have to pull it out a couple of times a week to clean the filter – we use small-mesh netting as a filter, somewhat rolled up and stuffed around the entry way to the pump; it collects the detritus in the water, and slowly clogs up, reducing flow to the waterfall (which is how I notice that it needs cleaning again!)
Pulling the pump & filter, in it’s one gallon bucket, out of the water can be quite a challenge, leaning out over the water and trying to lift the bucket with no handle (especially when there’s lots of dirt in the filter, making it very waterlogged and heavy). Once out, I unwrap the filter netting from the pump, hose it clean (into a big container that collects the dirty water, and then is dumped at the bottom of the garden).
Once clean, I wrap and stuff it back in the bucket around the pump, and lower it all back in to the water.
I do get a bit messy though!