my first line of "defense" is the hose washer with the screen- saved me big time once when it caught all the plumbers goop the used when reinstalling the hose bibb's for the season. stopped up the filter, could not imagine what would happen if that got into my system!
I then use a whole house filter that I set up with fittings for the hose. I found it much more economical in the long run to change the whole house filters and I can decide what type of filter I want always carry a spare and they are available at Lowe's, etc..
I also have an "on the go" water softener, really makes a difference.
a little off the topic....