Jef79answered grow question 5 years ago Hello.. Hope you are well.. Yes it is just algae.. Its not a bad algae either tho so wont hurt ur plants.. Same as fish tanks, u get gud algae and bad.. Green algae is usually not harmful at all..if u think it looks unsightly then just pop a cover over ur pot once she's big enough and the darkness will starve the algae and it will cease growing.. Stay safe n gud luck with her.. 👍🍀