Help! Green Hair algea bloom

[marie]

Well, the water changes aren't a factor. The green algae bloom as well as a brown algae bloom has all occured since I did a large water change after treating for cyano.

Thats the problem with using chemicals to get rid of cyano. You don't find out what causes it and just end up with a different type of algae.
I would suspect a combination of, lights and nutrient build up , maybe in the rocks or sandbed