You should make the salt water and then add it. Are you setting up a live sand bed? If so, definitely add salted water to the tank, otherwise the sand will die off from the lack of salt. Also, the shrimp should be table shrimp from the supermarket, nothing live so no need for any type of flake. The premise is to create decay for the shrimp to start your cycle. You should add that dry rock when you do this, and I would personally add some live bacteria. Either from a bottle or,a few pcs of live rock for the Lfs
. This is only my opinion, but it will get you off on the right foot.
Also, are you using RO
water, because most municipal water systems are treated with either chlorine or chloramines and this will be deadly to,your system.