How often do i have to change my line?

Unless there is obvious damage or deterioration, once a year should be OK in
normal circumstances. Serious match anglers and hard casters change it more
often. I even know some anglers just reverse it at the end of the year,
exposing line that hasn't seen daylight and using it for a second year. I
assume we're talking about nylon line, braid lasts indefinately as it doesn't
deteriorate, just wears. Cheers, Norman.