How do I care for a Grammatophyllum?

[AWade]

I was recently given a beautiful grammatophyllum, but I have no idea how to care for it. It’s got TONS of roots and when I unpotted it, it was like a brick. There was no way I would be able to break the roots apart with doing major damage so I decided to just place it in a slightly larger pot and hope for the best. It’s got three new growths popping up and seems to be rather healthy. I’m unsure as to what species or hybrid it is because it is not in bloom, however there were two spent flowers in the root mass that appeared to be a dark red color with yellow outlines. Anyways, I’m super excited for this plant and any care tips would be amazing!