I hear they like dirty water, Cold water, lots of flow, no flow, lots of light, Low light, iodine. I had them before and they just melted away to nothing. a friend gave me some and they are doing fine. I cant explain it. So what works for some may not work for you. What works for you may not work for me. The only 2 things i did the 2nd go around is i kept a better eye on my pH making sure it stays at a constant level using buffers or the 2 part solution. also using some iodine once a week.