Tom: DO NOT use any silicone that is not marked _safe for aquarium use _as most contain arsenic to prevent mildew. You will be looking for a catastrophe! Tom asked: Anyone see any problems using GE's 100% clear silicone in a planted discus tank. How or is this any different between the GE silicone and "aquarium silicone" Good luck! Merrill Cohen Aquatic Gardeners Association