>I just started a tank about 4 weeks ago and put some live plants in.
>Now I am getting a dark brown or black coating on the leaves and rocks and an
>diver I have in it. I was wondering if plants are causeing the
>coating or is it something else in the tank? If you rub on the leaves
>it kinda comes off but I am lost on what it could be. I took the
>plants out in fear of it wrecking the rest of my setup or the fish.

    This "mysterious" black stuff growing on your plants is a beloved
thing called algae.
     That is not what you should be worrying about though.  What the
real concern is, is why do you have a DIVER in your tank!!!  We notice
that you didn't mention that you had any "black stuff" on the little
treasure chest that opens and closes with air bubbles! (Few! thats
     It may not be algae though. Studies by the Dept. of Underwater
Management and Maintenance In Emergency Situation (DUMMIES)  have
shown that submersible toys , especially those embodying human
figures, can cause extreme trauma to those fish commonly found in
hobbyists aquariums.  This trauma causes the fish to excrete a
blackish substance coating the source of the stress, in hopes of
relieving the anxiety.