Chadd:

A couple notes.

First, choosing line is not a matter of estimating fish size. For example, 6-pound test is not necessarily for 6-pound fish. You can catch fish much heavier than 6 pounds on 6-pound test mono. If you’re catching fish in the 1-6 pound range, you could probably move to 4-pound test, especially if you’re not going to be fishing in heavy cover.

Monofilament line is a single filament of nylon and has great performance characteristics for all kinds of fishing. However, you have to remember a few things about it. First, it stretches a bit. It gives. You can tell this even by experimenting with a length of line about 2-feet long. This may affect sensitivity and hook-setting power, but it also gives you a “shock absorber” function. Second, mono absorbs water, which makes it weaker — I have read that after an hour or so in the water mono may be 10 percent weaker than its rated strength. Finally, mono is strong, but it’s not particularly durable — it gets scuffed and scratched and cracked. After an hour or so of fishing or after a good fight with a lively fish, you should be checking your knots and re-tying a lot of them just in case.

Fluorocarbon is, technically, an advance in fishing line technology. It is stronger, more durable, and has other advantages over mono. However, a lot of people (me included) think of fluoro not as something that is BETTER than mono, but DIFFERENT, with different uses. Here’s what you need to know about fluoro. First, it’s not a single strand of nylon, it’s a more molecularly stable construct, which makes it stronger. This means that you need “less” line for the same strength. Second, fluoro is nearly invisible underwater. This is not to say that mono is really super visible, but fluoro really vanishes — do some experiments. It’s really pretty dramatic. Third, fluoro is more durable — it doesn’t get abraded or cracked, and it doesn’t suffer from memory (staying coiled up). On the other hand, it’s also stiffer and harder to work with, especially when tying complicated knots or when using heavy line. Next, fluoro doesn’t stretch as much as mono. In fact, don’t quote me, but it may not stretch much at all, and when using it some anglers miss the shock-absorption of mono. I have also heard people say that fluoro is hard on rod guides and reels — it cuts into metal much quicker than mono. One of the main differences between mono and fluoro that you’ll notice right away is that fluoro is much more expensive — as much as twice the cost.

So, to summarize:

Mono: cheap, strong, stretchy. Be careful. It gets scuffed and cracked really easy.

Fluoro: not cheap, stronger, not stretchy, very stiff. Hard to work with sometimes, may wear on your equipment quicker than mono.

Personally, I use mono in my spinning outfits. Mono is a known quantity for me. I know how it acts, I know how to use it, and it’s inexpensive. That is not to say that fluoro doesn’t have its uses — it’s great for a leader, especially where durability is a consideration. When fishing in sandy or rocky areas, and when going for fish that are hard on line (tiger muskie), a 3-foot fluoro leader is really handy.