Give it a good rinse with fresh water after use along with letting the line completely dry prior to storing with a reel cover and you should be good for at least 3+ years or better.
Don't soak the reels by submerging them for an extended amount of time. That is a noob move that could prematurely break down the braid if it doesn't dry properly.
I've got reels with braid that is 6 yrs old and will still slice thru your finger like day one if you try to pull and break it.