Hello Algonquin and, welcome to TPT! The short answer to both of your questions is yes. However, we must also take into consideration your light intensity. So, to grow plants you need light, ferts and, CO2. Different plants require different levels of each. DHG requires at least a moderate level of all three plant needs. Your DHG may be browning for several reasons: 1) it was grown out of water and is transitioning to underwater growth or, 2) you are in short supply of one of the three main needs of aquatic plants, most likely ferts and, medium intensity lighting. Do some searches on the interwebs about the needs of DHG and let us know what you are already providing and perhaps we can help habe a lush tank of DHG!
Stock lightly and carry a big filter. - I don't have aquariums. I have ecosystems in a glass box. - Hygrophilaholic and hoarder of Anubias.