My advice to you is feed live food on the day you purchase them. Yes blood worms will stay alive for a week, but remember your lfs would have had them for a day or so before you bought them and they would have been bagged up and transported for a few more days before your lfs got them. So be wary when buying live food. Once they die they will decompose rapidly and pollute your tank. If you really want to feed fresh food such as bloodworm or daphania or there is a wide range of frozen fish food on the market. They are sold in blister packs frozen, they have been gamma treated to kill off any harmful bugs and all you do is to pop out the number of cubes you want into a small dish, add some tepid water just melt the ice and then feed them to your fish.
Your fish will relish them as much as if they were alive and wriggling. and you know the meal won't have any harmfu bugs. Something you can't guarantee in live food.