Re: False bottom vs Hydro
Either one will work and you are right about surface area. You don't really need more surface area for bacteria growth because there are plenty of other places for bacteria to grow. It also isn't aqueous so you don't have to worry about fouling the same material that the frogs breathe as you would under water. I used to use hydro balls and they worked fine, but I started using egg crate because of weight, ease, and I started to silicone the layer off completely so that substrate can't get down into my drainage layer. This makes my builds much more stable over the long run. You can silicone your fiberglass separating layer with hydroballs, but they are a lot more shifty so there is a lot more pressure on that silicone. That's just me, though. I am sure everybody has their own reasons for doing what they do.