Greenish algae on the gravel

Hi all, I'm new to the list and I have a question.  I've heard that 
there are numerous types of algae that can grow in the aquarium, each 
having an optimal method for control.  The algae that seems to be 
running wild in my 30gal planted tank is:
 green, not hairy, mostly located on the gravel and rock (as opposed to 
the plants) and is resisting the efforts of 3 panda corys, 2 oto cats 
and several glass shrimp.  I've read that the ramhorm snail will 
sometimes eat algae, but will it eat my plants too??? Could someone 

Adrian Hydon <aph at globalserve_net>