Who came up with this guideline?
Does it really effect your filtered tank's levels that much?
I don't like how mine look with this advice, too much gravel for my taste...I'm not cheap or anything,
it just doesn't mesh with the image I'm going for.
Don't most good bacteria live in the filter media, and not the substrate?
If I need more, I'll get it, but if not, I'll stick with less.