Most definitely. I just started up a 10 gallon dwarf hairgrass "grow out" tank. Im running right about 15wpg with pressurized CO2 and ADA ferts. Balance IS the key. It will take you a week or two to figure out how much CO2 and ferts you need. Just keep messing around and you will eventually get it. Also, with hairgrass, keep trimming it. This will make them send out runners so your tank fills in quicker.
The first pic is my little 8 gallon that had 18wpg, pressurized, and ADA ferts in its early stages.
Once you have hairgrass filled in, then you can let it grow tall and lush. The second picture shows my tank near its final stages. As you can see, its nice and green and lush. Dont be afraid to go with the 8wpg!!! It did take me about a month or so to get everything dialed in to where there was no algae. Good luck!!