That would be hard to do without C02 IMO. To get a carpet like that needs CO2, good ferts and even better flow. There are ways around the non C02 though, carpets can be done without. Take for eg, Riccia, this is a quick and easy carpet and wont need C02. As for the scape itself, i think it's obviously do-able, however, i would love to see someone new to plants be able to pull something like this off.