Plumbing/water-pressure question?

there must be lots of mud or something (rust) in the pipes if the filter is clogging up constantly, replace the water pipes and hot water service which the landlord wont do, test the water quality.

Remove the cartridge and fit a bypass connector. You may get a lot of crud out of the tap but at least you will have full water pressure.

An alternative would be a cheap Chinese filter that connects to the outside of the faucet - which you can wash out yourself.

Or you can plumb-in a larger 10" filter unit which will take longer to clog up and you can replace the filters cheaply yourself.

< everything is fine for two weeks and then the pressure gradually starts decreasing >

Something is fouling that cartridge. Not much you can do except put in a temporary jumper and then open the tap full, blast the crap out of the lines, remove the jumper and reinstall the cartridge.

It can't be that great of a "quality of life issue" since you've lived there for 16 years.

Either move or live with it. The cost of replumbing the building would be tens of thousands of dollars plus the lost rent since the units couldn't be occupied. The tenants would see an a ren't increase upon lease renewal.

it's likely impurities in the water -- which is beyond their control. look at the cartridge next time they replace it ... if it's all crudded up or hardened, that's water problem