gravel. From what I read I should have used Flourite. I'm thinking of
replacing the gravel with it it, or at least mixing some in.
What do you think?
Thanks!

It will help a good deal. Plants will have better color, health and
root systems. Certainly worth the $ IMO/IME.

Regards,
Tom Barr

Mark asked:

What is Flourite and why is better?

See above on the better part and it's simple, no layering. It also is
easy to work with, holds roots down better than other stuff I've used,
makes replanting easier.
SeaChem makes it. It's a simple gravel that is great for planted
tanks. Rinse 3x and add to the tank.
That's it. Last forever and no iron is needed etc. There are other
more subtle issues that make it good as well.

Regards,
Tom Barr