Yes...Actually, a breeding pair of angelfish would live and breed perfectly in a 36g of your dimensions.........For example, my local store that breeds discus and angelfish, breeds his pairs in 20-30g TALL tanks.......Substrate, or gravel, is not needed...Keep the tank simple.......A pair of angelfish and a long, bushy plant for them to lay eggs on........By the look of number posts you have, you may be a newbie, so trust my reply, I know.........