algae question

so i have gambusia and 1 bladder snail, the water has become green, there is no light besides the flourescents in the room they are kept in, i have a scraper for when it grows on the sides, but how do i keep the algae in the water and provent it from turning the water green

I just started noticing this the other day! About my 3rd week of cycling. I first saw it on the sand than it started growing on the ferns, wood, and rock! It is very fluffy looking and very light brown in color. I have a little bit of diatoms in my other tanks, but this seems very different...