Water Turning Green in a Fish Tank

When you put ​tap water in a ​fish tank it ​shouldn't ​turn it green ​in a couple of ​days but this ​happens to my ​water, as seen ​in the picture. ​

fish tank.jpgThe water ​tastes slightly ​tangy, which ​means it's ​most likely ​acidic. Maybe ​acidic enough ​to strip pipes? ​Because it also ​tastes slightly ​metallic. ​

I think the ​house is on the ​end of the ​distribution ​system because ​there is little ​to no chlorine ​in the water. ​

it is ​also ​possible that ​there is an ​overdosing of ​sodium ​bisulfite, ​which could be ​the reason for ​little to no ​chlorine. ​

Would there be ​any other ​reason as to ​why the water ​would turn a ​fish tank green?​