I originally bought 5 or so plants of each of frogbit and dwarf water lettuce. Fast forward 3 months or so and my entire 6 foot tank has been covered - I am completely fine with this and expected them to grow quickly. However, I'm only seeing 1" to 1.5" of roots hanging down into the water column. My goal was to cover the mid-water level in roots for my exodon shoal to swim/dart in and out of. I'm not seeing any root length at all - does anyone know if there's anything that can be done to grow them out longer rather than have the plants continue to propagate up top?