I think they need to be outside Tarev as Cem suggested. I put mine out a long time ago & only brought then in overnight when we were going to get freezing temps. They get about 6 hours of full sun & they really began to take off when I put them out there. The only thing I would worry about with yours being in the water in the glass is that it might get too hot & almost boil with the sun getting magnified through the glass.
