You can find more info on your plant on this good Tropica site. http://192.38.244.204/go.asp?show=products

You will need more than 1/4" of substrate I'm afraid. 1" to 2" is good, but of course more expensive. Just a word of warning on the Ecco, there was a bad batch that may still be around. The problem I've seen in posts is that it floods the tanks with phosphates and in some reports water hardening compounds. I would keep an eye on these levels.

The shop you went to looks super, if a bit boutique like. The trouble with designer shops is that you pay for the label and the decor.

Ian