I noticed awhile ago that algea (green?) was growing on my fake silk plants in my 10g tank. So I removed the plants and cleaned them, did a 30% water change and changed the gravel. Now the algae is worse.. it's grown back on the silk plants, it's growing on the gravel, and on the glass in the 10g. What causes it and how do I get rid of it?
Also, could this be harmful to my fish? They're female bettas.
Thanks!

Thanks!