Is Maracyn Two Reef Safe?

[DarthFred6996]

The insert says it is. It says it will not harm your bio-filter. Is this true? Yes, I am paranoid.

 

[panmanmatt]

No it's not reef safe. All antibiotics will have some effect on your bio-filter. Antibiotics kill bacteri which is exactly what your bio-filter is made of.

It may not kill it off completely, but why take the risk. Move the sick fish into a hospital tank and treat there.