Water Lettuce Questions

[LyraGuppi]

I hope I posted this thread in the right spot, this subforum seemed the most appropriate.
I'm doing a bit more planning on the (dreaded) 90 gallon, trying to figure out what floating plant I'd like. Water lettuce seems pretty doof-proof, and I love the large root structure. When I get the lid elevated, there should be about 4 inches of growing space off of the surface of the water. I should be able to provide bright lighting for them.
Finally, I have a few questions:
I heard the roots hold on to debris and make maintenance hard, is this true? I remember reading on another forum that they'd rain debris down if disturbed.
Do they mind bright and possibly warm lighting (T2 bulbs)? The lights will be on top of an elevated sheet of glass. Everywhere I've read they need bright light, but I'm worried about burning them.
Should I mist them, or attempt to keep them in a humid environment? 
 
Thanks for tolerating my excessive worrying. c:

 

[Byron]

I have no experience with T2 fluorescent so I can't say if that is low, moderate or bright.  But generally, floating plants being close to the light source rarely have issues with too little light.  But too intense light can cause problems.
 
If the tank is covered normally, the air will be fine.  Open tops won't hurt either.  I have grown Water Lettuce in my garden pond during summer, but also in several covered tanks.  It has for me tended to remain much smaller in tanks, which is good; I have had it reach 4-5 inches across in the aquarium, but it is easy to periodically remove a larger plant and stay with the smaller daughter plants that will grow.
 
Sometimes the roots can attract organic matter, but I would not worry about it.  I have noticed that the plants in tanks with no fish and less fertilization develop incredible roots extending down into the tank.  Quite the effect.  I assume this is some form of attempt to assimilate more nutrients, which would be fewer without fish.
 
Byron.
 
Edited to add "not worry" in para 3. 

 

[LyraGuppi]

Thank you!