Fishing reel question. Can you use 6 pound test line on a reel rated for 8 pound yest?

You can go a little heavier or a little lighter with no problems, 6 pound or 10 pound would be fine for a reel made for 8 pound test. It will work with 12 pound, but the thicker line will cut down on the reel capacity, as well as making it harder to cast. Like Ghost said, you can get around these problems going heavier by using a braided line like Power Pro (since it's thinner than monofilament, but stronger), but it's also more expensive.

The reel will probably be strong enough to handle pulling with line up to about 17 to 20 pound test. You could load it with heavier braid, but it wouldn't gain you anything as far as pulling power.

You don't want to get a huge reel and fill it with thin line -- it would take hundreds of yards of line to fill it, and the reel would be so bulky that casting would be near impossible. Normally what you want is a rod and reel matched up for a certain line weight, whether it's 2 pound, 8 pound, 20 pound or whatever.

You can use a super braided line and use a heavier pound test because super braid is very thin and this way you can use the same line for for the fish that you want to use 8 pound for but then use it for the fish that you want to use 12 pound test for. Power pro is a very popular super braid.

this sounds like common sense would answer this. therefore it sounds like you are trolling.