Aha, the seller told me that it is indeed the intense lighting. I should keep it on the background
Interesting. Okay, more micros. My rummynose tetras were about 3.00 each and they school great. I got my rummynose's from a good reliable source, the ones I bought were fully acclimated to pH of 7.6. My rummynoses all survived.I agree with Cavan, add more micros.
Intense light won't cause myrio to go pale like that. I've seen it growing in ponds around here in direct sunlight for the entire day which is far more intense than tank lighting.
Also, low nitrates tend to show up as pale new growth that steadily gets smaller compared with old growth, and usually you will see old leaves start to turn yellow and decompose as the nitrogen is moved from old leaves to new leaves.
By the way, I'm trying to get rummynose tetras for my angelfish tank. I've got 6 fully grown angels at the moment. The rummies seem to be pretty expensive though at around 3$ each. How much were yours and how well do they school together compared with your other fish?