I'm pretty new to bass, been at it all year. Recently I've started developing blisters on my finger, middle and index, on my strumming hand. At first it'd take around five hours to develop, but it got faster and faster, now I can't play for 30 minutes without getting them, and they take days to heal. I need to know if I'm playing wrong, or if theres something with my strings, ect. Haven't had lessons, just came from guitar.

Thanks in advance.
Just keep playing through it, let them heal completely before you start playing again and try not to pop them. If they do pop cut the skin off and let it heal. After a while your picking fingers will start to callus up. It takes a while but once you've got them it takes a little more to get those blister. You could as be picking too hard, try picking the string a little less hard and that may make it better. I've been playing everyday for about 4 years now and sometime when I get into a good flow and am rockin hard I get those blisters still, so it's just something you've got to learn to avoid by trying different things out. Hope this helps.
Stephen @ Relapse
Thanks, guess it's something that just comes naturally then, looks like I'll have to put up with it. I can always pick, huh? :P