Sorry I could not reply faster. You lose less then 5% of your Lumens through the water with the Fresca Sol. The fact that you have better CO2 use, can put the bulb 5 inches from the plant, and have better temps would negate that 5% loss.
I believe you can use it in a vertical grow. I don't think anyone has done it yet but I know it can be done. You don't need a very large pump because you want the water to flow slowly thus gathering the heat around the bulb. I have been told that you want just a bit over 100 gph to flow through your light system. I would say you can run the water jacket downwards or if you need to slow the rate of water, run the flow up through the bulb and out the top.
I would imagine you would be the first to try this application.

BTW nice plants!