couple of questions: white anubias leaf & Plant ID (stem plant)

Quite interesting on the Anubia leaf. Never seen one spring out like that. Maybe just hasn't came into it's pigments yet?

As for the stem plant, it looks to be Najas.

Sometimes my plants sprout new leaves that melt right away. I never know why, especially since the rest of the plant is healthy. I would remove it though so that it doesnt decompose and add nutrients to the tank.

The little plant is guppy grass, which I cant seem to grow planted. It grows fine floating for me, but slowly dies if I plant it. Grows fast though, nice plant for fry and shrimp tanks. Great covor and lots of surface area.

The only time my anubias's do stuff like that is when they want something lol. I vote some kind of nutrient deficeincy. Generally a squirt of flourish does the trick for me.

If you notice both plants are showing the same symptoms with very light green/white new growth. This clearly points to a nutrient deficiency. It's hard to tell exactly which nutrient is deficient as different species react differently.

My first guess would be Mn or Fe or one of the heavier metal nutrients. These are generally not transported very well and show symptoms in the young leaves first.

Your sword plant behind the hitchhiker is also showing some signs of deficiency. You really should look into dosing some fert's.

Here is a link for nutrient deficiency in some aquatic plants.

http://www.aquatic-eden.com/2009/06/common-aquatic-plant-deficiency-diagram.html
Hope this helps. ;-)