Spaghetti & Crab - crock pot recipe request?

I've made spaghetti and crab before on the stovetop and cooked the sauce for 3-4 hours. Comes out fabulous. Just a basic spaghetti sauce with blue thrown in. I'd like to do this same recipe tomorrow evening but won't be around all day. Has anyone ever done this in the crockpot? I have two bags of frozen blue and a couple of crab legs to throw in. I could use some recipes and advise on how long to cook and on what setting if you've done the crockpot version before. Thanks.