There are some critters that will eat cyano's. However, this is like giving your kid cold medicine to cure a cold instead of making your kid wash his hands often to prevent a cold. One of the things that never gets asked is how did I get my cyano bloom.
Cyano's are heterotrophic bacteria which basically means they get their food from dissolved organic compounds. Well, we certainly introduce a lot of those to our tanks don't we? We can remove some DOC's with Granular Activated Carbon and water changes but we can remove even more with a properly sized protein skimmer.
You can use E.M. to help rid yourself of cyano but it really is a band-aid approach and that's why I don't recommend it EVER unless someone is so frustrated they want to leave the hobby. Not only that, there are unintended consequences such as bacteria dieing that we want to live. E.M. doesn't only kill cyano's. It's an equal opportunity killer----it kills the good bacteria too!!!
Because cyano's are a blend between an algae and a bacteria, you should also do the normal things you do to prevent algaes. Such as......
Do not overfeed----ever. Normally, this revolves around uneaten food but in this case, the major problem IMO is excess fish waste (which will degrade into DOC's).
Always use RO/DI water if your municipal water supply adds phosphates to their water (as most do). You can request a water report from them.
Never overstock your tank.
Use a quality protein skimmer.
Check on the photoperiod you are using and make sure your bulbs aren't so old that they have experienced a color shift.
Increase circulation to get the waste suspended in the water column for your skimmer to pick up.
Run a phosphate test on your food. Take some RO/DI water(read the manual....not all test kits work in freshwater) Get a baseline reading of your water. Write that reading down. Next, let some food soak in this water for an hour. That will give you an idea of how much phosphate is going into your tank each time you feed. BTW (soaking food like this is a very good practice to limit input of phosphates into your system).
