And trace elements Newer tanks are usually ok. I had 6 let the water get bad based on bad advice. Ended up with over 20. Increased flow and improved Majors and trace elements and they have tripled in size. They will wander to where thry like the flow.Definitely want to be sure... anemones usaully require a year first but I am having success after 8 months so it all depends on your tank's water parameters