Quote Originally Posted by tebstan View Post
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?
So, if I did not do water changes for months and months that most likely would be the problem for the cyno? Also, maybe the amount of food.

How do I tell if I have enough flow in the tank? Any articles talking about that?

RO/DI setup has been going for a long time now so that is not new. The tank has been going for a year. No changes from routine. The one big thing I have not done was water changes.