Right now I've got a 20L that is just about done with it's dry start and after a few drinks last night apparently I thought it would be great if I bought 3 things of HC. I have medium light but won't be doing CO2, should I give them a shot or just try and sell/trade them? The substrate is MGOPM with a sand cap by the way.
If you let the HC grow in for a while to develop their roots it should be fine. This is anecdotal only, but for one of my tanks I did a DSM with HC and now it grows very well under barely medium lighting with no CO2. I'm sure it could be almost explosive under higher lighting with some CO2 addition, but I only have to trim it once every month or two, which makes me pretty thrilled.
My little patch of HC seems to do just fine without co2...it's about 1 square inch now and has actually doubled in size since January. I stuck it in a piece of filter floss a couple months ago, most of it melted, then it decided it wanted to live...no dead bits on it at all for the moment. Kind of afraid to try and pull it off the filter floss and actually plant it. I seem to have somewhat better luck keeping plants alive if I DON'T fuss over them as much as I think I should.
Forgot I had a picture of it...took this about a week ago. I figured I'll just let it do its thing where it is and see what happens.