Decorative Marbles Can I Use These Instead Of Gravel In My Aquarium?

Can I use these instead of gravel in my aquarium? - decorative marbles

I want to use a Bio-Rad, as the leak, and was told that the gravel is not really necessary. I think it would be strange, but just something on the floor. There are two halves of marble decorations in mesh bags, you simply type in most stores where you buy glasses. Would you a small amount of them on the floor of the aquarium?