Floating Plants

Hi

I have a new 64L tank that when cycled will eventually home 6 Dwarf Neon Rainbows and 10 Neon Tetras. The lights in the hood are very close to the surface and I was wondering if this will be too bright for the Tetras. I'm considering floating plants as I have read that Tetras like shade from direct light. The questions I have are..

Which plant (if any) due the size of the tank?

Is the lack of space between the water surface and the lights a problem?

Will the Rainbows also appreciate the shade?

I would appreciate any advice 

I have Salvinia in my tank, though I've never been able to decide if it's S natans or S. minima. It looks like a small cluster of leaves each about ¹/₄ inch across, and short roots hanging underneath. The flow from the filter keeps it at one end of the tank so I have a bright end and a shady end - I have live plants at the bright end and silk plants under the salvinia.
The salvinia usually grows very well, I have to throw handfuls in the compost at regular intervals. But this summer I lost nearly all of it. Natalia came to the recue and told me it was the heat that was the problem. There was still a bit alive so I left the tank lid ajar during the hot summer and it is coming back well. Heat like this can affect other floating plants (I think) so it is worth bearing in mind whatever you get. It never happened before as we've had terrible summers since I got it 


Edit to add the link

I'm not a plant expert I'm afraid so I'm not sure. The led's on my betta's new tank don't run very hot compared to the T5 fluorescent tubes I have in other tanks so you might be OK.

Oops 

That was a typo, I have T8s not T5's. Appologies.


I bought the Salvinia in Jan 2010. It was sold as S minima but it looked like the photos of S natans as well so I never knew which it was. It grew and grew. I had to throw handfuls in the compost bin every couple of months. Then when the hot summer started this year, it went grey then brown and died. Well, most of it did. I saved some green plantlets and put them in a tub. Natalia told me this is a problem with floating plants in hot weather, made worse by the water evaporating more readily, then condensing on the lid and dripping on to the plants. The high temps then heat the drops of water which burn the leaves.
The rescued plantlets were fine in the tub, then I put them back in the tank and left the flaps open while the weather was hot. The plants started multiplying. Then last week, I found them nearly all dead again. I rescued a few, which then died in the tub of water.

Why did my Salvinia thrive so well for three and a half years then die? The first die off I can understand, it was the exceptional weather. But October was no hotter than the previous three summers, and it didn't die off during them.

I am now a bit wary of suggesting Salvinia. There are other floating plants that seem very popular - Amazon frogbit and water lettuce. I am not very good with plants so you might want to research those and see if they would be better in your tank.