Change your fishing line before it becomes brittle. Exposure to high or very low temperature can reduce the life of your line.
Don't use the same line for more than one season. Even if the line is stored properly, being left tightly wrapped on the reel caused the line take the shape of the spool. This is called line memory. Twisted or curled line will shorten the distance of your cast and tangle in the guides.
When is it time to change your line?
This question is frequently asked about fishing line, and the quickest, safest answer to give is, "AS OFTEN AS YOU CAN POSSIBLY AFFORD TO CHANGE IT!" Unfortunately, this is not a very responsible or accurate answer for anglers that "just don't know". Many serious anglers replace line daily! It is almost a compulsion, because serious anglers are looking to reduce every risk of losing a big, or maybe trophy sized fish, which often occurs because of a weakened or worn out line. There can hardly be a more sickening or more frustrating feeling when "the big one" gets away due to a broken line.
Line does not wear out or degrade as it sits in your garage or closet. Line wears out from use. Anglers need to inspect line often, and look for two indicators that would prompt a timeout for a re-spool. One indicator is physical wear and tear resulting from line contacting rocks, logs, sand, rod guides, boat rivets, propellers, fish or any other sharp or abrasive objects. Most contact is usually limited to the last 2 or 3 feet of line. Inspect this two or three feet often and cut off when the line is nicked or abraded. When has nylon line been worn and abraded to the point that it should be replaced? Certainly when any abrasion or nicks appear on the line beyond the first few feet. Most fishermen replace their line long before the line nicks or abrasion is visible to the unaided eye. This is a judgment or "comfort level" call that each and every angler needs to make.
Another indication that the timing is right to re-spool is when line becomes less manageable with repeated cycling from wet to dry. Nylon line that is fished and saturated on the weekend, and dried during the week, is going through molecular structure changes. When line is new it quickly looses its excessive springiness and tendency to coil after it becomes wet and is "worked" with a few casts. As line is repeatedly cycled from wet to dry, the line takes more casts and more time in the water to regain it's manageability. Eventually, the line needs to be replaced to gain the manageability of a new line.
When to change line depends upon the fishing conditions, the fishermen's tolerance for risk, and the fishermen's past experience with the line. But choose the right time, and line, based on these two indicators, and you won't be sorry!
Courtesy of Shakespeare