I am growing glosso, HC, 2 eleoharis species, plus Japanese hairgrass for 4 years now. one of the easiest to grow is actually HC I don't even water it in winter maybe once a month i use forest soil with some laterite added to it A trick I do is that if I want to enrich the soil in the tank after a year I remove the soil together with the grass (if you let it dry a bit it comes out as a sigle piece, like this lawn carpets) then you can add fresh soil under it, wet it and place the mat on top, this way you have renewed soil for the already overcrowded HC to run into.
Also lots of times once a year maybe grasses can die this is no problem for most of them, in most cases HC will start all over again, in the beggining with tiny leaves that start expanding to cover the whole bottom. HC will flower if it feels threatend and will grow all over after dying.
John I think that if a tank is "fully" balanced with no algae whatsoever you can grow any grass and have no algae problems it is just a matter of how mature your tank is with all it implies.
What I am trying to say is this that even if the HC was grown emersed if the tank is not balanced after it is filled up and the photo is not taken the first week after fiiling it you still run a high risk of algae manifesting specially with all this rich uncovered substrate in case of soil, now if you grow it emersed in aquasoil (specially one that has been left submersed for some time to leech stuff before using emersed) that is much better.
