"Barry" wrote in message
...
I have a 29 gallon setup with standard gravel and UGF. My Java Fern is
incredibly lush and the Java Moss grows like nuts. Both were doing
great even without CO2 or PMDD (which I've recently setup to try and
revive a rotting Crypt).

My feeling is that gravel substrate is perfectly fine for the fern or
moss because they are not deep rooting plants, they will attach to the
gravel or whatever you have in the tank. My moss has attached to
gravel, sea shells, rock, and driftwood.

Java moss and fern will also grow with no substrate at all.
Steve