If we were to apply Rain-X, Rain-X Original Glass Treatment—The Invisible Windshield Wiper, to the inside surfaces of our aquariums before adding the water, would that be an effective repellent to GDA and GSA? Rain-X is a siloxane containing material, and some siloxanes are used as food additives, so it might not affect the tank life forms. But, would it prevent algae from getting a good grip on the glass? Hey, I'm serious here, so stop laughing!