I am in the process of setting up my 55. While looking at the Dr Foster and Smith website, I saw a substrate called Instant Aquarium. It is in 20 lb bags, in gravel or sand, wet packed. It supposedly has all the cycling materials in it, so that you can basically dump it in the tank and you are fish ready. I think I might try it, but would be interested in knowing if anyone else had tried it before and what was the result. BTW, I am still going to start the tank with something inexpensive, like some danios or tetras. Just wondered what luck anyone else has had with this or a similar product.