I bought some Riccia off a fellow member, and if I recall correctly it was at least mostly lime green. I removed some bba and put it in an open jar to grow it out more at the window, which receives plenty of direct and indirect sunlight. Dosed 1 drop of excel every other day, but now the Riccia is getting more and more light colored, in fact it's all like a white/light brown. The only green I can see is on the very tips of the bits, and so tiny as well!
What am I doing wrong? Should I just stuff it in my tank and hope it revives itself?
Excel DOES kill riccia. When people want to get rid of riccia that's what they use. Fortunately riccia is super easy to grow. You can put it in your aquarium or even grow it immersed. I have a tub with dirt and plants and one of the ones that is thriving is riccia. Hope this helps