I usually do it about every other spring. 3

Changing your line at a set time during the year could mean you are fishing with worn out line, it all depends on how frequently you fish and under what condition. Monofiliment is very susceptible to abrasion, Spyderwire, much less so.

Since you are conscientious about your line, I suggest buying an inexpensive brass spring scale like this what this does is has a marker that you can reset every time the scale is plunged, it tells you how far down, or the maximum tension was given.

By tying a knot around the end of the scale and pulling until it breaks, you can see at what point the line snapped at. If it is close to your original test strength you purchased, then your line should be fine..

there is a caveat to this process, and that is tying 100% knot strength. Most people have difficulty in doing this, and some knots will simply never be 100% knot strength no matter how you tie them. So the only way to REALLY know whether your line is good is to do several break tests on the line in question, then do several break tests on NEW line using the same style of knot.

Also, many fishermen simply cut 5 or so feet off each time they start a new day fishing, this coupled with the occasional broken line requires re spooling well before a season is over, furthermore having 100% knot strength could be detrimental to your fishing, for example, if all of your knots were 100%, and you developed a snag, then where would the line break? sometimes, tying a knot with less than 100% strength is done purposely, for example, if you fish a dropper loop, or any set up that has your hook above your weight, then tying a weaker knot on the weight gives you the chance of retrieving your hook, possibly with a fish still on it, rather than loosing the whole set-up. winkydink