Baby Shrimp Not Growing In Months & Other Problems

Have a little hunt in the plants for s dragon fly nymph or a damsel fly nymph. Did the older one show signs of white line?

At first he seemed to not have the white line, but then I bent him a little with a toothpick and the white line appeared on his back like someone had cut him through.

As for the nymphs, we live near an artificial lake and the room has a balcony with plants. I do check from time to time but I guess those are big enough to be seen. Until now I've never seen one in any of my tanks. Also, no new plants have been introduced to the tank lately.

 

I don't know if I've mentioned calcium food I use as I don't use cuttlefish but it is used, I think you may already be feeding some of this!
Spinach, kale, broccolI stem, okra, the list is huge but those above are what I use, even I have to ask for help sometimes so iam going to have a chat with a local shrimp friend to see if we can shed some light as to what going on, your water perameters are spot on your feeding the right food yet there seems to be a moulting issue which I thought may have been the problem that came in with the shrimp and they've not adjusted to your water, as I've said before you've an excellent knowledge on shrimp you know what your doing yet this is so frustrating for the pair of us, iam sure we'll get there, someone else reading this may have an idea which would be welcome