I dont have pictures as my lights are off right now, but is there such a think as red corraline algae? I have numerous red patches on my rocks. I was told that you should be able to easily scrub these patches with a tooth brush to loosen it up as the first indication is that it was cyano. Low and behold, after scrubbing a few patches, I didnt make a dent. I scratched it with my nail and it felt rough and calcified like corraline. As such, does red corraline exist? Or could it potentially be something else?