At one time I had a reference site that showed the light needs of different plants and how to obtain it with different types of lighting. It had heights of the light, lumens, K ranges and the works but it has been a few years since I looked it up. Now this was for aquariums so it may not be the best reference but aquariums need higher light than anything else so if it works through water it should work for terrestrial needs.

As for slow growing, moss is one plant that I have never liked because I have not been able to see growth fast enough. I know I am going to be getting some and I will hate it but I really want to give the frogs a place to get on the ground and not get coconut coir on themselves all the time. That and having a place for them to crawl out of the water and not be directly on the substrate seems like a plan for my next terrarium.

I once had a moss that I was sure I killed, forgot about it because I figured it would just decompose and go away. A lot of it did and after nine and a half months it came to life and thrived for the 4 years I had it in my plant area I had some years ago. My conditions here are quite the opposite of most places so it takes a long time for anything to acclimate that isn't considered temperate.