can you take a pic of your tank and show us what you have,i thought cyno was red but you keep telling everyone what you have is green so maybe its not cyno.I have to clean my glass everyday or it starts to turn green and with you being gone for 3 days it might just be a build up, i would try and feed something else beside flake food, i know from your other posts that your picky with the looks of your tank(not trying to start an issue here) but maybe its normal algea that everyone has in there tank, i have some spots that are green and then turn to purple so thats why i ask if you could post a pic. Just dont hate on me.lol