
Originally Posted by
tebstan
45g is too much at one time. It's better to do smaller, more frequent water changes on a regular basis. If cyano is the only problem, keep it off the corals and address the cause. If you do a big water change, it will still come back if you don't figure out what caused it.
What kind of corals do you have? You mentioned putting in liquid food, but some corals won't take liquids. That food could just be contributing to your problem. Cyano comes from high nutrients and low flow.
You may still need to add more flow depending on your rock structures. But most likely, you've got high nutrients feeding it as well.
Did you recently switch from tap water to RO? Or add a bunch of fish, or liverock? Make any changes in the routine?