one of my shrimp have molted

You will be very glad you set up a refugium as it enables you some flexibility!!!! For instance I just bought a Cleaner Shrimp the other day to have a couple for my 125, however the shrimp is so small that if I placed it in my tank it would surely get eaten, So because I have the refugium, I put it in their as it is a shelter til it gets bigger for me to put in the main tank!

 

so in hindsight its another tank outside the main tank with dsb some lr rubble ,macro algae , a inlet pump . i stick the protien skimmer in there and that returns the water to the main tank ..? am i on the right path .

 

Yes Matt that is more or less the jist of a refugium! To provide a safe environment for pods and other valuable food stuff to grow for your live stock in your main tank. The ability to have more water volume and surface area, house delicate inverts etc. without worries of them getting eaten by more boisterous members of your main tank, a place to cultivate macro which will compete for the same nutrients as microalgae and to place more live rock and live sand for bacteria population increase.