I've heard that people use fluorocarbon on a whole spool even though its for making leaders. Is this type of line good enough to put on a whole spool, is it light enough to use for light lures??? need everybody to answer.

umm no. Fluorocarbon is meant for reel line. Fluorocarbon leader is meant for making leaders. People just use the fluoro spool to make leader instead since its extremely cheaper.

They are excellent for spool because you dont need any knot or tie. For me its either braid then fluoro leader or straight up fluoro.

I really think it's just a matter of preference.

I fished straight flouro for a short time before switching to braid & learning
knots, so now yeah I just run a leader. Mostly because I can get lots more line capacity with braid vs: mono/flouro
If you're gonna run straight flouro, I would shop around & find the limpest,
most castable you can afford. look at sunline & seaguar blue label

there is a big difference between the Fluoro line material and leader material.

I use flouro leader for leader as it is much tougher. I'll use it where the leader might be in highly abrasive areas like oysters, rocks, etc. I don't recommend using fluoro line material as leader...it's qualities are much different. If you don't want to use fluoro leader material then heavy mono is fine.

I use 30lb braid as my main line on a casting reel and then if I'm in shallow oysters or rocks it a 25lb fluoro leader.
If i'm out deep where there arn't many obstructions i might use a monofilament leader in 15 or 20lb

20 lb mono leader is also fine for wading the grass flats.

Flouro has it's place. Not so good as main line because it is denser than mono and will sink. Unless you need to fish small lures deep in deep water. Think of it like sinking line. It is usually also stiffer. Mostly I just use them for leader material for their abrasion resistance and near invisibility in water.

As a Leader, the100% Fluoro Leader Material can't be beat for toughness and abrasion resistance.

In general, (and yes, different manufacturers have different specs for each line) there is a big difference between Fluoro leader and Fluoro line material. Most Fluoro Lines are actually copolymer and are sometime softer than mono. Yes, cuda killa is spot on about it sinking. but it isn't much.. the difference in specific gravity (a measure of density) between fluoro line and mono is only a couple hundredths. Flouro line material as a main line probably has more of place as an open water line with no structure around and works well in clear water. I've found it to be more limp than mono... to be clear, this is Fluoro line material, not leader material; It's totally different. Personally, I've known quite a few others that did not like the Line material and choose mono or braid over it as a main line for saltwater use.

I use flouro if I'm fishing a lure. I would use braid for a cork since the flouro will sink and can mess up hook sets or action on the cork. If I'm fishing off the bottom I would use braid with a flouro leader.