If that was real coral I would love it. You can achieve a more natural look without breaking the bank too, I mean pool filter sand looks natural and is like ~$5-$20 for all the sand you would ever need. River rocks from Lowe's look great IMO and are dirt cheap. Get some super hardy cheap plants and you've got a much more natural look than fake coral. And gather your own driftwood, everyone loves free right?
This is meant to be nothing other than constructive criticism. Like the gentleman above me said, A for effort!