[Ifurita]

I've found Sphagnum to be quite easy to grow in lowland conditions: It'll grow even if only given bright shade(some sun is better though) and air humidity can be quite low as long as humidity directly around/next to the plant is high.

Since your moss' growing points are small and its only reviving(not mature yet) right now, you may want to give it extra TLC. Keep humidity high(can use cover) and conditions around the moss wet. Too wet is better than too dry; I've found sphagnum to grow happily even when underwater(abt 1-2cm deep) so you don't need to worry about it drowning. For light, bright is good, but not direct sun.

Do NOT keep air humidity high combined with low light conditions. The sphagnum will grow very quickly, but thin and stringy. Its not healthy and will die easily.

Note that there are a couple of different strains/species in cultivation by CP growers in Malaysia and Singapore and some might grow better in lowland conditions than others. The stuff I'm growing may be one of those and that's why I find it easy.