here I heard people say that it had too much synthetic crystal in their colony and I figured how is it possible then my question is that what the synthetic crystal can grow? or can we grow it?
Synthetic Crystal is something only the LIS Ice map and Zolarg Ice map can grow. For players to be saying there is too much, it is probably because not enough people have started importing it in order to balance things out. Personally, I haven't gotten around to importing yet and I need it for the tech 'Next Gen Power Production'. Others may be in the same situation.
but is it that a synthetic crystal deposit can multiply alone?
The Synthetic Crystal does multiply so you don't have to keep making more (and apparently it grows quite quickly).
and well it is super me that believed that it was necessary to plant it every time its relieve me now