42G Lighting Recommendations

[Ruth]

I agree with Nano however if you think you might be upgrading to a larger tank any time in the next year you might be better off to go with 250W lights as you can always raise them higher off the water surface. I use a 250W penant as the only lighting on my 44 cube that is 18" and it works just fine. The bonus is that I can get a larger or deeper tank and this light will still work just great and save me the cost of having to replace my lighting.