With no knowledge of your lighting it's hard to recommend anything but the easiest one for me was dwarf sag, by far. If you're higher up on the lighting scale you could give hairgrass or microsword a go. It really depends on what kind of grassy look you are going for because they all look a bit different.
Just had a look... It's a JEBO R48 sporting 4 flouresnet bulbs (55w @ 10,000k) for a total of 220 watts.
Kind of grass I (think) I want would blanket the entire floor of the tank and I guess look pretty close to the real deal stuff.
But really, not sure... Never really dug into the veggie side of aquaria besides (hopefully) providing a growing environment and dropping in plants that appeal to me. Compelled to admit but, not even sure the names of the plants I have
So 220w on a 75g. Well that's not bad at all and should be fine for a carpet. Microsword is a good choice and looks grassy like a lawn. Hairgrass is more like a fine, thin leaved lawn and sag is like bushy grass.
Carpets look good but to be honest, I gave up on them ages ago because they can get to be a maintenance nightmare and I must be too lazy
I'm loving eriocaulon cinereum because it grows at a snails pace and looks dandy too.
i have dwarf hairgrass with 2.5wpg and its growing great. its been swarmed with BGA and BBA and its still going strong and sending runners all over the place. even before ferts and CO2 it did great. the only trick is that it comes in a clump of about 100 tiny little plants and you have to pull each one appart because they're all attached by runners, and use tweezers to push each little plant into the substrate at even intervals around the tank.
this is an old picture, but it kind of shows the grass
here it is more recent, still not growing in 100% but getting there. behind it is dwarf sag and on the far right is microsword, which grows VERY slowly.
RockabillyChick- that substrate is filling in nicely. I started with eleocharis (hair grass) myself, not too long ago and really like the look and quick growth of it. I'm growing it in a low-light 2.25 wpg/55 gal. tank and the results are very nice. Under 3 wpg it is growing even better.
Another good choice, IMO is E. Tenellus which gets just a bit taller and grows from a single crown.
