Welcome to the site, but if you're not careful you will toss out all your bass equipment and go all out on the crappies...lol
The reel may have several line size recommendations printed on the spool, and I would go with one of the lower "pound test" lines from that list. In real clear water, you might want invisible line, but in stained water you could go with a higher vis line. If your water is loaded with brush you may want something a little heavier than if you're in water with few hang-ups. Go with the lightest line you can successfully use because lighter is more sensitive