Shimmer Effect

[Otter2009]

Does anyone know of a way to get a shimmer effect in a tank without surface agitation? I would really like to have a shimmering effect in my tank but I run CO2 and don't want to lose any by running a wavemaker.

My tank is a 36 gallon bowfront that runs two LED lights.

 

[Autumnsky]

If you have any outflow ripples, maybe a little light directed at a sideways angled down. I have seen some flexible neck lights you might be able to bend one near there.