Sorry, we got a bit off topic
Slaphppy was just amazed that I killed duckweed when everyone else just can't get rid of it.
I can now handle both aquatic and houseplants.
It's just a question if finding the right plant for your tank. Even when a person has several tanks, a plant may grow well in one tank but die in another.
For small tanks, salvinia and frogbit and maybe water lettuce; for larger tanks, water sprite is suitable too.
Are these live plants, and if so what kind? Some plants need a lot of light and floating plants cut down the light which isn't good for high-light plants. There are ways of confining a floating plants to one area of a tank so the ones planted in the substrate can get enough light.