So every time I get a new paly or zoa, the stems are generally pretty short. The zoas tend to be so short you don't even see them.\r\n\r\nHowever, after a while of being in my tank, the stems seem to grow and become kind of long. The question is why? Is it a flow issue? A lighting issue? They look fine otherwise and they maintain color and propagate.\r\n\r\nI have a 40 gallon tank with a 150w MH and 2 24" PC lights.\r\n\r\nAny thoughts or suggestions are appreciated!