Any of the puck style LEDs (acting as a light point source) will create 'shimmer.' Non-point light sources, if high enough above the water, will do the same - I've created shimmer (called the 'caustic network' in scientific works) with NO fluorescent lamps. Of course, water surface agitation is a must. There was a study published years ago that showed pulsed light created by this phenomenon boosted rates of photosynthesis.