We use an outside filter canister that attaches to the water hose and uses a standard 0.5 micron carbon filter that also filters sediment. We got the canister and filters from rvwaterfilterstore.com, although I don't our canister on their web site now.
Most RV filters filter out the sediment but not the harmful chemicals and bacteria which is what I worry about. Good filters are available but are expensive and require frequent changing if air gets into them, causing bacteria to grow, which happens to the portable ones each time you disconnect the water supply. We only drink bottled water when using the rv and do not use any filter system, although we did use filters years ago but decided it was not worth the inconvenience and expense.
Sometimes I feel we all worry to much.