Aquarium Water Abnormally Green

Hello Everyone! I'm back from my 1 month vacation to Germany! Such a wonderful place! But when I came back, (The tank was cared for and water changed regularly, water is tested regularly, Ammonia 0, Nitrate 0, Nitrite 0, Ph 6, Chlorine 0, chlorimanes 0, water hardness=soft, the typical from a well cared for tank.) the water was abnormally green! Usually you would excpect a minor green in aquarium water, but [bThis![/]b] is abnormal!





Comparison

Please Help me!!

Post in tropical dicussion more members go over there.
My son went to berlin a few months back and he loved it.

Ok, I'll post in tropical dicussion. Thanks wilder. Any further viewers please post in tropical discussion, same topic title. Come here for pics.

what food they been eating? i had food that turned my tank red before so its a possibility