Why Is There Scum On The Water Surface

A couple of days ago we received an email from a young man who has just started out in this hobby and has setup a small [tag-tec]saltwater aquarium[/tag-tec].

He was very apologetic for contacting us via email but had noticed that there was a large build up of what appeared to be scum on the water surface of his aquarium and was hoping that we would be able to help him find out what it was, if it was detrimental and how does he remove it. [Read more]