[klaus777]

do you have any other red plants doing this? or any green ones doing funny things?

 

[klaus777]

I sort of agree with what chagovatoloco is saying if I may add a twist. My understanding is that green light is not usable to plants, it is only the most visable light to humans. The pigment will change in plants from receiving improper light spectrum. The deal with red plants is that they come typically from deeper waters where green light is reduced and more blue light is what penetrates. The reason green plants are green is because the chlorophyll absorbs red and blue spectrum light and reflects green spectrum. {The green portion of the color spectrum is so abundant in nature where they grow, they would probably wither and fry from too much of it, (only my hypothesis)} so again, they reflect green and that's how we see them as green. A red plant being for deeper water with less green spectrum doesn't need to reflect green light as much as it's green leafy buddies. Red plants absorb blue light and reflect red light.
So even though you have a good watt per gallon ratio, you might be giving too much light in the green spectrum.
I myself have a Tiger lotus along with many other red plants and it is as red as a beet and I use less powerful wattage with a nice full color spectrum. What type of lighting are you using?
That's not to say that is your problem. How long have you had the tiger lotus and has it always done this. Sometimes it could just be that particular plant itself doesn't carry a heavy red pigment.