The micron cartridge is used 'temporarily' to polish the water. It clogs very quickly and is not meant to be run in the long term. Mine usually clog completely within 2 days so that the water flow slows to a trickle. The cartridge then has to be removed and bleached.
I run a few HOTs with microns and despite heavily stocked, well planted tanks, I only need to swap out the carts about every 2 weeks. If yours is clogging every 2 days your water is a lot dirtier than it ought to be.
Yeah the micron cartridges are good at polishing, mine clog from 2 days to 1-2 weeks. If your wanna it continuously, you'll need two atleast, basically 1 in use and 1 being cleaned.
I swap my out every week and it keeps my tanks water very clear. Its good to have at least a spare to swap out like it was said above ^ I also slide a filter sleeve over the micron cart and it helps keep the cart cleaner longer.