Not really sure but water sprite are super hardy, mine is growing like a jungle and I would need to get rid of 1 bag worth every 3-4 week. I even tested it by cutting a branch off without the root to see if it would grow, and surprising it grew. I even kept 1 bag worth of water sprite in a container outside in the sun with closed lid and those grew too so it doesn't need ferts. The container was only filled with RO water the first time, after I sold those water sprite, the second batch was filled with RO water and 1 root tab. I can get picture of it tomorrow if you want.