This ad is for a small portion of Microworm starter culture.The difference between a large culture and a small culture is the time it would take for you to use the culture.So if you have some time, you can make many cultures using this one starter culture; however, if you are in need of a culture yesterday, I do not recommend purchasing this listing. There are other sellers offering larger quantities which is ready to feed as soon as you get them.Here is some info in helping you decide what type...