Hi.
We have in our house a whole house water filter.

It is an American Plumber housing, model WC-34PR.
Until recently, we did not know it existed, so it has not been replaced since we bought the house, 2 years ago.
1st question: If we replace the filter and clean the casing, is there any problem continuing to use it?

Our water sometimes has what seems to be grains of sand in it.
The drinking water, which is filtered through a reverse osmosis, under the sink filtration system, tastes excellent, but still seems to have small white particles floating in it.

2nd question: I would appreciate your assistance in understanding what type of whole house water filter, is recommended for this type of Whole House Filter casing. How do I know what fits it and what does not?

3rd question: I saw there are many different types- polypropylene, spun polypropylene, string wound, carbon, cellulose and more. I am uncertain what I need and would appreciate your assistance, explanations and recommendations, regarding the differences, before going to buy one.

Thank you in advance!
S.E.

American Plumber is a good filter housing, just clean it well, lubricate the O-ring with some plumbers silicon grease and use a string wound filter.