I had some cultured some for quite a long time, I got it form Salty Fin. but this week it froze, I left it out on the window over night. I still have some left in the fridge that I havent used. I dont know if it can still be cultured but you can have it. Now if you want a fresh culture you can go to salty fin and get some then start culturing that your self. I stoped using it cause my tank is over stocked and how new york steelo says " the fish pee and poo feeds the coral" LOL