Forgot to mention, HC is not a demanding plant but if you can give it CO2 and more lights, the better.
It does need a high level of nutrients. They are usually grown emmersed so it does take time to acclimate it.
Mine took about 4 months and a lot of patience.
Based on my experience, here is what I have observed.
During the acclimation period, you will see some leaves turn dark green.
I think this is a process of it changing to a submerged form. Whatever you do, don't pull on it. It is still growing. It will look like it's dying but it's actually shedding leaves and stems and growing new ones for the submerged life.
Yes, some will die (melt) but don't loose heart. It is a slow grower unlike glosso. When I say slow, really slow. Here is a picture of my HC at about 8 months since I planted them. I only bought one small pot of HC and what you see now is equal to about 20 small pots.
Cleaning the substrate with HC is impossible. The plants will do that for you.
Regular water changes and regular hardware maintenance is all you can do.
Good luck and wish you success with HC.