Used several types for years... The best thing no matter what machine (Even the best $2,700 machine) is minimize the moisture as much as possible, hard to do with fresh Halibut and Salmon, but wipe inside of bag with a paper towel or put a small folded towel inside to catch excessive mositure, it will seal and you'll have food that last a long time, 6-9 months to be on the safe side, course never had anything that lasted longer anyhow.................. It was eaten before it could go bad...