After several failed ideas, I finally settled on this 'glass spout'. I wanted somewhat of a curtain of water, as opposed to a pipe or tube, to flow over the roof of the iguana house. I wasn't able to make it too wide, however, as the pond is not all that wide. I just made a little wood frame for the piece of glass, and siliconed it all together.
The first clear silicone leaked, so I went with some white stuff, that worked out well. In earlier pictures, I showed this 'spout' from the inside (under the roof), with the 3 tubes feeding it from the bio filter.
There's the spout in its final form, spilling water.