Well, I'm pretty new at this, but I use "No More Algae" tablets or another such product. I pride my clear water, esp. in my living room, as well as my outdoor pond. I would make sure my filters are clean (inside and out) since I've not had this problem. Move tank away from direct sunlight and keep water parameters strictly on board. Green water in an indoor tank does not seem to be an appropriate response to me. Sorry

__________________
55 gal. tank-3 Koi, 3 Shubunkin, Black Moor, 2 Goldfish, 1 Calico Telescope, 2 Sarassa Comets, 1 strange Fantail.