Thanks again, the neo tank has many hiding place and should be ok with tap water and I have silver tips, cardinal and rummy nose tetras and hill stream in it.
I just got back from some aquariums that have 6-7 shops in a block and saw some of the shrimps that look like that baby shrimp, called snow ball and they are selling like SGD$1 think those might the unwanted from CRS. I saw a you tube video of a shop guy talking about snowball from CRS Shrimp stall in SG been there before but only look they are a few breeder shops here but too much for a newbies like me.
I seen many YouTube and local breeder saying RO water for keeping cardina shrimp and as I starting just about 4 months it more an experiments to see if I will continue keeping CRS or maybe go deeper .... but for now I won't add any more to the CRS tanks to see if it crash in the near future.