So I am new to this hobby, tank has been going for 3 months. I have noticed about 3-4 spots throughout my 100lbs of LR that have about dime size spots of cyano. At least I think its cyano....it is more red/maroon than my purple coraline, I can scratch it off, but it takes work and a strong tooth brush. It doesn't look slimy, have bubbles, or anything else, but not sure what else it could be. I lowered my lights down to 9 hours a day, did a good cleaning on my skimmer, and adjusted flow. (2 korailla 3s and 1 korilla 1) Now for my main question- should I be worried about this amount of cyano as described? I google images the stuff and it just shows people's sand and glass covered in it....i just have a few small spots but am worried it will get worse all the sudden. Also will this small amount of cyano harm my corals? I have a mushroom close to some on a rock and it doesn't seem to be doing well....just curious if it may be related. Thanks for help guys!