It's becoming more and more complicated trying to remember what lb line I have on every reel, because I have 3 of the same rod/reel and 10 more rods after that. What systems do you guys use to keep track of this?

I put a piece of tape on the side of the reel and write it on it. Ugly but it works.

Model decals, electrical supply houses have sheets of numbers in small sizes. Pull the sticker off with the right size and put it on the reel. When I did this in the past, I put it on the inside of the handle where it could be seen but was mostly out of sight.

Another easier way is to simplify you line choices. I know that mine is 6 - 10 - 15 or 20 and I can tell the difference by sight.

Normally I have a general idea by what i have tied on each setup. Plus I only use 4-5 line sizes anyway.

50# or 85# braid on all of mine. Pretty easy to keep track of that way.

I put the size on tape on the lower handle of the rod. Also, the majority of my spinning reels are Mitchell 300x so I take a marker and put the number under the spool. And, Man - do I have extra spools !

Write with a sharpie on your reel line type ( Floro, mono, braid ) and pound test. I also put the date i put it on. when you need to change take alchol and wipe the writing off. I am experimenting with a color code system using colored elctrical tape green=braid, blue=floro, white= mono and writing the pound test on there because after a while the writing on the reel tend to rub off. I wrap the rod where the rod and handle meet with various color tape and write the pound test on it.

numbered stickers and i use to keep a 0-1" micrometer around but no if i loose a sticker and cant tell what it is it gets stripped and new line on. jmo.

I can tell by looking at the line.

Another system you can implement is to use rod wrap on your handles and use different colors for different sized lines.

WHITE ADHESIVE TAPE,FELT TIP PEN, DATE, MFG,LINE WEIGHT WRAP AROUND CORK IN FRONT OF REEL.

I can't tell the difference in the 10-12 12-15 15-17 17-20 flouro. I use tape on the cork and a sharpie. Cut up Band-aids have worked when I couldn't find the tape

I use these instead of rod wraps.
http://cableorganizer.com/heat-shrink/heat-shrink2.htm
You can get them in any color/length and coordinate that way. You don't need a heat gun to shrink it. I use my girlfriend's hair dryer. Protects the cork too. Measure your cork diameter, but I mostly use the 1in. except for swimbait rods and flippin sticks.

Jay..pretty cool..I did something similar..when I wraped my rods with tennis racket tape, I chose different colors, for the type rod and line I would be using..

I just use my brain and remember what line is on what reel.