Why Arent They Growing? Rcs

[Sweeden]

So a couple of years ago i had a shrimp tank and the shrimp blossomed really quickly.
 
I started back up this year, this time with ONLY RCS. 
 
I have had one batch of babies and they have been 2mm long for weeks now. I haven't seen any moults anywhere.
 
What could be wrong?

 

[Baccus]

It is very easy to miss shed shells, it could be that the shrimp are just eating them really quickly. Or it could be that they are not shedding and that could be down to a water issue e.g. is the water too hard for them and making their shells too tough. Also what temp are you keeping the shrimp? Cherry Shrimp like warmer water than say crystal shrimp, and the warm (22-26 degrees cel. I find seems to suit them best) water encourages rapid growth.