I don't think it's faster emersed, but it sure is easier. I have in both submerged and emersed and while the submerged growth is faster it sure is a little more trouble than the emersed growth which requires little to nothing from me. If you can provide it a good environment go for submerged to get bulk, but keep some emersed in case that crashes, this way you will always have a starter piece again.
My emersed grows faster than the submersed, I use a spray bottle with a weak fertilizer solution on it every third day or so and it is going gang busters. The light is two small PC bulbs one 7 watts and the other 13 watts both 6700 K. I'm getting ready to start a larger emersed culture this week.
Who said I abandoned my crypts? Besides, this stuff is actually nice to look at and does what you hope for, unlike that "Pellia" mess I watched so many people get sucked into. It doesn't overtake a tank like glosso and Hemianthus micranthemoides, it doesn't float up like riccia, it doesn't make a mess like java moss... it's a nice little plant.
What is the recommended substrate texture for HC? fine or coarse. Does a product like Flourite fit the bill? As far as I have read, lighting intensity requirements are in the mid-range, can anyone verify? Who has been growing this plant with success? (I already know of Oliver Knott's aquaria and photos).
Mine seemed to spread better in eco-complete than it did on flourite, however hard to say for sure as conditions in the two tanks were very different, the eco-complete tank was purely for HC where as the flourite tank is my community tank. Also grew well on some xmas moss:
You can see a little of the early progress here, I had to cover it in my community tank as I have fish that would otherwise uproot it, it eventually filled the patch of fine grained gravel but didn't go much beyond that, making me think it didn't like the flourite as much. I took it out of this tank however as the cover idea just didn't look to good. It's now growing in a glass jar under a light on a bed of moss. In the eco complete tank instead it filled in all the space that was receiving good light however I haven't been looking after this tank much so it's looking pretty sick right now. Mostly growing it emersed until I get time to look after another tank.
That job of tender loving care you applied to the diminutive HC sample seems to indicate it is one of the most ungrateful plants about.
Most of the Flourite I use is covered with coarse quartz sand. But I think I will go and study Oliver Knott's gallery again. He has some photos of the planting process which are helpful. In case anyone else is interested, his gallery is at the following link:
I have been growing it now for about a month or two now. I have silica sand mixed with fluorite and it seems to grow pretty good in this mix. Another month and I should have my whole foreground covered.