Discus aren't crazy active like africans or cory cats, but they're still pretty lively fish when they're comfortable. They have almost an intelligent awareness about them in the way they swim around the tank searching for every last morsel of food. Their persistence never ceases to amaze me. If they see a piece of food buried down between some leaves, they won't stop trying until they get it. It's almost like they think about things before they do them. It's very different from other fish and it's absolutely absorbing to watch.
One thing you'll want to consider is the placement of the tank. It's extremely important. Make sure you have the tank somewhere where you'll spend a lot of your time. For me, that's my computer room. For a while, I had them in a tank in my bedroom and, although I'm in there a lot, I was always in and out and they never got used to seeing me there. They would run and hide any time I went anywhere near the tank. Now that they're back in my computer room, they're alive and personable. They come to the glass to beg for food and all that.
Most of the stuff you hear that discus need isn't all that big a deal. They'll do great even in hard, alkaline water. They do fine with lots of light or just a little. They even play nice with Angelfish and plenty of others. However one thing you can't skimp on is water changes. I do 50% at least twice a week and there's still a noticeable behavior difference before and after the water change. They get less active and kinda sluggish if you let the water go. As it gets worse, they'll get skittish and they'll hide a lot. I've even had one freak out and dart around the tank non-stop until he hurt himself really bad and had to stop and hide in a cave. I did a water change and he was back to his normal self.
