Hose filters are cheap and there are four quite different reasons to fit one, each needing a different cartridge. Buying the wrong one is the usual outcome of shopping before deciding, so it is worth being specific about which job you have, because in one of the four cases no ordinary cartridge helps at all.
Protecting equipment: sediment
Filling a water tank, feeding a pressure washer, or supplying drip irrigation with fine emitters. Here the enemy is grit, rust flakes and pipe debris, and a straightforward sediment cartridge handles it. Choose a moderate rating rather than the finest available, since hose pressure and flow are modest and a fine element becomes a bottleneck on a long fill. Fit it at the tap end where the tap supports it, and expect a modest drop in flow.
Ponds, aquariums and sensitive plants: carbon
Here the target is chlorine, and a carbon cartridge reduces it usefully even at hose flow, though filling slowly gives a better result than opening the tap fully. Chloramine is a different matter: it needs contact time no hose filter provides, so check your utility's report before relying on one. For fish in particular, a dechlorinating product dosed into the water is more reliable than a cartridge whose remaining capacity you cannot see.
Drinking water in a caravan or boat: certified, and a proper hose
This is the one case where people drink what passed through, and it raises the standard. Use a hose designated for potable water rather than a garden hose, which imparts taste and is not made for the job. Use the filter for sediment, drain it between trips so it does not sit wet and warm, and understand that no inline hose unit is certified to make water safe. The source still has to be a supply you would drink from.
Car washing: no cartridge does it
Spots on paintwork are dissolved minerals left as droplets dry, not particles, so sediment and carbon cartridges leave them exactly as they were. Only deionizing resin removes them, and it is consumed by the total dissolved content it removes, so on hard water it is used up fast. Use it for the final rinse only, or dry the car instead, which costs nothing and achieves the same result. Our whole house filter guide covers treatment sized for real household flow.
Questions people ask about water filter for water hose
Which cartridge protects a pressure washer or tank?
A sediment cartridge at a moderate rating. Finer elements become a bottleneck at hose flow without protecting anything extra.
Will a hose filter make campsite water drinkable?
No. Inline hose units are not certified as drinking water treatment devices and do nothing about bacteria.
What stops water spots when washing a car?
Only deionizing resin, since spots are dissolved minerals. Sediment and carbon cartridges leave them untouched.
Does a hose filter work on chloramine?
Barely. Chloramine needs contact time no hose device provides, so check which disinfectant your utility uses.