Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Choose the material properly and a small light from under or above, but really close to the edge of the material will give some interesting effects. The material would be outside at the back of the tank, but not attached too close. Just enough gap that a small light can shine on it.
The most impressive of these I have seen was a blue plastic, I think it was rigid, and the light was from the top, middle. It looked like moon light. The plastic was glowing in a small area, maybe only 1/4 of its surface. The rest was dark, but not black, deep blue.