I have live blackworms that I get from a pet store. It seems like all they need to live is refridgerator temp and clean water. Depending on how many worms and how much water will be the deciding factor as to how much you have to change it. If you have a lot in a small container, the water can get dirty in about 12-24 hours. That is how mine is.
Current fish (includes all 3 running tanks): Polypterids, severums (of which I raised from eggs), gouramis, plecos (gold spot ones & a gurupa), loaches (zebras, yoyos, & a kubotai), macculocchi spotted silver dollars, an African butterfly fish, & Ctenopomas (a leopard & an ansorgii)