Basically saying DHG is just easier to care for? wonder what I was missing in my prior failed attempts. I have been able to grow most anything just not that. One thing I wanted to improve on was my substrate, I had basic gravel before and will have ecocomplete in the new tank, I think the smaller granuals will help.
I have DHG and eco complete. I think its not a good match, even established DHG unroots easily and its a pain to get it started. What I did was let the DHG float first to let them root and when I plant them I plant them deeper than normally suggested otherwise bottom dewller fish will unroot them. Since the eco granules that settle on top are bigger I don't think the DHG will rot unlike if you planted them deep in other finer substrate.
Lighting - Summertime I only burst my 2nd T5HO, the DHG does not grow during this time, it only grows when both T5HOs are on all the time. Its on a 38G I think the lights are about 19" up. So it needs a lot of light.
So think about the other plants in your tank, if you mix high light and slow growers you will get algae unless you have a perfect balance in your tank.
Fertz - I do modified IE and root tabs. I also have a layer of laterite and peat underneath but not sure how much that contributes to the DHG I put those in mainly for the swords.
CO2- tons, smoked my Amanos at one time. :-(
Easy care? I don't think so. I think they make the most mess too. They do look great when it carpets.
Hope this helps.