led lights

I was just looking at those on ebay and they stated the recomended height is 12-16 inches above the water. Go to Sea of Marvels in North Liberty and check out Hungs tanks. It will give you a good idea of the look and power they have.

 

To help with setting the height you should also be able to borrow your region's par meter and test the par at various depths after you get the lights hung where you think they should go. Assuming they are dimmable fixtures you can either adjust the intensity or raise/lower the lights to tweak the par values to where you want to be.