if you were open to something modular, i'd suggest moss on stainless steel pads. these would be movable and would offer a low growing carpet of sorts
I am certainly open to moss. There are a few out there that really interest me. I think doing any other kind of carpet would be tough, and I would fear it would get out of control fast.
Plus, while my light is better than the stock light, at the bottom of the tank I think it is still on the high low side. Also, I am not doing CO2 yet. I have a plastic diffuser that I was thinking of using in conjuntion with a DIY type style. I got it and a glass set on the cheap here. If I can get by without CO2 I will.
I have not started using any liquid fert yet either. Not sure if I should yet.