Red wendtii is tolerant of low light like the other wendtiis, but its coloring gets rather pale. To see it in its best coloring, you should have around 3 watts per gallon. The leaves become heavily bullate (wrinkled) and dark as dark chocolate with deep red undersides.
I have one in a 20 gallon tank with 120 watts of light. Yeah, some of you guys may think I'm insane, but my plants thrive and I only has one minor algae attack. The leaves are turning green on me but they are growing really well. Hope that helps.
Got a question on this plant. Does anyone here have any personal experience with how big(small) they will be. They will be in a tank with a little over 2 wpg. In a 46 gallon bowfront, would they end up as background plants?
My experience has been that it does not get that large for a wendtii. Four or five inches, and in good light, the leaves tend to be shorter than that. I would say it is good for a dark colored midground plant that contrasts nicely with light green plants.
In my experience, Cryptocoryne wendtii 'red' is perhaps the largest of the wendtii varieties. It can easily reach a height of 12 inches in a couple months. I have seen pictures of this plant reaching all the way to the top of a 21-24" deep aquarium.
Cryptocoryne wendtii v bronze ('Tropica') is a much smaller, more manageable crypt. Undulata and petchii also could work nicely.
I have to second what Tsunami had stated. The wendtii 'Red' I know gets HUGE in a large tank. However, I'm told they will stay small in a smaller tank. Whether or not this is true, I'm still trying to test it out. But then again, I'm not really sure what a wendtii is anymore :? .