"Then what"? I don't know your water. I tend toward overkill when I do some things. BBFS-22 Pentek Two Housing Filter System gives you two big housings, the bracket, and the interconnnection. Initially I would put a PENTEK-DGD-5005-20 heavy duty filter cartridge into the second housing. I would initially leave the first housing empty.
Also I would get a spare O-ring. Pentek 151122 O-Ring. I have not needed a spare yet, but it is good to have. I do not have bypass plumbing around my filter, so a bad O-ring would put me out of service.
You should only tighten by hand, but the 144368 SW-4 Wrench for 20" Big Blue aids in removal.
Note these are big housings. So they are heavy when full of water. So you want ready access.
Smaller housings are probably sufficient. They would be lighter. A single housing might be quite enough. I got my 3 Pentair Big Blue 4.5 housings before I knew I was getting the iron+sulfur backwashing filter. So there is not much to do. I leave the first housing empty. The second one has a DGD-5005-20 polypropylene spun 50-5 dual gradient 20 gpm filter.
The third housing has the PENTEK-WP1BB20P polypropylene wound WP1BB20P 1 micron filter. You also need a small amount of food-grade silicone grease. I got Molykote 111 in a 5.3 oz tube. That will last me forever. When I apply grease, I use nitrile gloves. Others use a lighter weight silicone compound. Do not use petroleum jelly; that is bad for the O-rings.
I changed the filters after 13 months, and it looked like I could have gone much longer. If I had not gotten the backwashing filter, my cartridge filters would have had much more to do. You should have seen what I flushed out of my water heater. I also got a "boiler" tap after the filters and before the water softener. That can be good for drinking water if you like minerals, and it is a good place to screw a pressure gauge. It is also handy for relieving the pressure when changing the cartridges.
As I say, smaller housings probably would be more than enough for you. One housing may be quite enough for you. If you get 10 x 4.5 housings, you could always go to bigger bottoms and filters later. The 10x4.5 and 20x4.5 cartridges are not proprietary and are available from many sources with different constructions. Do not use cellulose cartridges on a well.
I think that part of the job of the filter is to show you what was in your water that got filtered out.
http://waterpurification.pentair.co...d/en/310053-pentek-bigblue-specsheet-mr14.pdf