I ran into this problem when doing the fuge in my biocube.
There really are only two options, the jbj nano glo which I bought for $50 or a small light submerged in the fuge itself. In retrospect i probable should have gone with the small light in the water. LOL I spent a silly amount of money on that led
light and could have gotten the same result with the way cheaper option. The led
light is good quality and i may find a use for it yet after I break down my cube.