Question
I have a water lilly plant 2 year old and this year the pads are appearing brown and delaying, attached to the underside and all up and down the stems are what look like clear slug like things? What could they be and how do I treat it or should I just take the lilly out?

Answer
It is possible that those critters are eating all of the decayed organic matter that would otherwise be fueling the lily's growth.  I would take the lily out and try to lure the slugs out of the pond with some dry dog food.  Then you can add some copper mesh around the outside of the pond.  Just don't let it get in the water.