like i said, i have a tank that's water is the color of mountain dew, a limey green. the params are fine, 0 amm, 0 nitrite, 15 nitrate. it's a 12g eclipse with a betta and a little grey fantail goldfish. the water's been this color for months. ive tried daily water changes and leaving the light off but nothing seems to help. it is across from an east facing window so does get a couple hours light in the morning but not a whole lot. when i do a large water change and the water's looking almost normal within maybe 3 days it's back to being so green u can't see the back wall. there is no significant algea growth. a touch of brownish here or there but only a tiny amount.i'm also careful not to over feed. Any ideas?