"Easy" plants, lol. I've got a couple anubias that seem to be doing well, but I haven't had them very long, so I may be slowly killing them unknowingly. I bought some java fern, which was actually a bunch of little java ferns and left them floating in my 10 gallon. Howie loves them and is building nests in them :D They are growing these long green strings - I thought they were roots, but they are coming from all over the plant. Does this mean the plant is happy and growing?
I also have an Amazon Sword (the very first plant I bought), and he isn't looking so hot right now. The sword is in Rosco's tank, and Rosco loooooves this thing; he sleeps on it at night. I read that swords need iron, but maybe all he needs is a better light? The one I have in there came with the tank, which was left in my apartment when I moved in.
Yesterday, I bought some water wisteria for my newest (currently empty) tank, because I heard that those were rather undemanding plants.
ETA: The substrate I'm using in the new tank is sand, and the other 3 tanks are plain gravel. No fancy plant substrate, I'm afraid.
Perhaps I don't really need fertilizer for these plants?