Plus, some leaves protruding from the tank can look very effective.
The fourth is to use plants with some aerial leaves or leaves that sit on the water surface (like lilies). For these plants, dissolved CO2 is not an issue. They will not be CO2 limited at all and will grow rapidly, with the only limiting factors being light and nutrients. It is for this reason that many aquatic plants that are grown commercially are grown emersed (i.e., above the water) before arriving in stores. In this vein, most aquatic plants are also capable of producing aquatic leaves and aerial leaves, so given time and opportunity, your plants will happily rise above the waterline—though check with your local store to be sure. Plus, some leaves protruding from the tank can look very effective. Just be sure to raise your lights above them by at least several inches to a foot (depending on lighting intensity) to avoid overheating/burning the tips.