Dull-colored Cryptocoryne, possible nutrient deficiency?
My Cryptocoryne (I think it's a green wendtii, but I'm not sure) is growing dull-colored, narrow leaves, as you can see in the photograph. When I bought the plant, its leaves were broader, and a very bright yellow-green. I have since trimmed the original leaves as they became overgrown with algae, so you can't see them in the photograph.
Could anyone speculate as to whether the plant is showing a nutrient deficiency?
I dose KNO3, KH2PO4, and Plantex CSM+B; I am using a Fluval CO2 20 in a 10-gallon tank (which, to the best of my calculations, brings the CO2 up to around 15ppm), and T5HO lighting.
Could be the plant was being grown emerged when you bought it or shortly before. I am growing some wendtii submerged and emerged. The emergant growth tends to be broader and darker, while the submerged leaves tend to be narrower and "reach" towards the surface more, so I am not positive this is a nutrient deficiency. Could be normal, though I would be curious to hear input from others.