Here is what I’d do if you’re having trouble with floating plants or rooted for that matter: *Water Temperature needs to be consistently 80-84 degrees for maximum growth rate. A thin layer of Seachem Flourite or oak leaves within your substrate, recommended especially if you’re water is soft to add minerals. *If you have access to aged cow manure add about a golf ball sized amount per 10 gallons. Make sure you’ve met at least a Medium Light requirement. Make sure your tank is not completely overgrown could be too much competition. *If your using 100% artificial light, make sure you’re not using exclusively using cool white light bulbs, these have too much blue (cool) not enough red (warm) spectrum. You may try 3 or 4 different species at the same time to find what works best. When I receive a new aquatic plant that I’m not familiar with, it will be planted in several different tanks with different lighting conditions. i.e. A friend had given me some Hygrophila carambosa and said give it as much light as you can. I tried it out in one of my full sun plant pools in the greenhouse and found it did better in the semi-shaded pool conditions. You’ll also learn more about the care of your plants that way. * Suggestions that are especially beneficial for Dwarf Water Lettuce, Duckweed, Dwarf Water Lilies Hope this sheds some insight for you.