Help! I have had a snail outbreak in my 30gal tank.

What can I do to get rid of them? Do I have to go as far as getting rid of the live plants and switching out the gravel?

I am trying the cucumber in a baby jar trick tonight to see how many I can trap but I read that that will not get rid of them, just help control them.

Also, will having an outbreak like this harm the fish at all?