Yeah irydyum, that makes another good reason to use 24/0, falls under the enviromental issues catergory.

But I've said before the issue of 24/0 vs 18/6 or any other choice between, is a personal decision based on what works best for an individual in his or her own set up. I've used both for various reasons and now using 20/4 in one grow, just because I've got a few auto flowers in with my moms, and that was the recommendation as "best" by the seed producer. And the moms could care less (they told me).