For the pond surface (or bird bath bowls etc.), it is recommended you use a pool paint for the interior surface, the same paint used for painting the interior of swimming pools.

Outdoor paints that will work for the toad house and any surrounding decor on the pond feature are....Patio Paint, Plaid's Outdoor Paint, and even Plaid's FolkArt Acrylic Enamel if you want a glazed look to your surface.

Patio Paint requires no special prep and doesn't need a sealer and holds up well to the elements.

FolkArt acrylic Enamel can be baked on your pieces or air dried for 21-22 days to make it permanent. If using terra cotta you could actually bake your pieces in your oven. It's made to withstand microwaves and dishwashers so it will hold up well to the weather.

I personally still like to put a UV finish on my outside pieces to prevent the colors from fading over time. And to keep your pieces looking great for years to come, fresh sealer should be applied every year.

Thanks! You really helped. What UV finish do you use?

I use either a clear Krylon UV protection spray or Rustoleum Diamond Varathane UV protection brush-on water based finish. The latter I usually use on wood pieces, the Krylon spray on just about everything else. The Krylon spray would be fine for your project.