I have a gunite cave that will get plastered up to a line level with the bottom of the tile on the rest of the pool (no tile in the cave). So that will leave 3-4" of gunite under water. The PB will be coloring the gunite inside the cave to match other rock around it... What can I seal the gunite with that will waterproof it by be clear and not change the appearance of the gunite?

I also would like to seal the back side of the rock work around my pool... since when it rains, water seeps through and runs down the pool wall, even though the cemented in the joints and back side of the rock work which is a planting bed. I'd like to seal it with something. Appearance is not important since it will not be visible, but I want to make sure it is not a product that will leach into the pool if water does get through.