Don't sweat it. You will find that plants will grow in just about any
substrate. The reason substrate is so important is that many of us are
pushing the limits of a planted tank and the smallest details can make
the difference between a beautiful tank and a rotting garbage heap.

If you haven't put in very bright lighting and thought about putting
together a CO2 system and regularly adding plant supplements then your
gravel will be sufficient. And honestly I wouldn't even suggest going
to all that trouble in a ten gallon tank - unless you really know your
stuff messing around with water chemistry for the success of plants in
a 10g tank is an easy way to end up with dead fish and unhappy
children.

Stick to easy plants - the anubias was an excellent choice. Vacuum the
gravel less often than you have been (and less thoroughly) and focus
your energy on giving them enough light. If you do that then they will
do well enough to give you a beautiful planted aquarium no matter what
substrate you use.

-Daniel