Currently in the process of setting up a 129L tank Low Light Low Maintenace tank. And was wondering what are good easy to maintain carpet foreground plants? Was thinking of using HC but here mixed things about it, some say its easy others say its quitre high demanding.
You might try Crypt Willisi. It stays low although I would not call it a carpet. I have some in an excel tank with 1.8 wpg. I think it would work in a non co2 tank. Also I have tied java moss to rough flat stones. It can get a little unruly.
After growing out my hairgrass using the emersed technique, it is doing amazingly well post submersion with only Excel for a Carbon dose. I'm curious to see if it will still thrive once I stop dosing Excel (I'm hoping to eventually convert my tank to a low-light,low CO2 tank). My hunch is that it will.