If your moving existing stuff then the wait period is not applicable. In my opinion unless you have a way oversized refugium they do not do a significant amount of nutrients control for you. I use mine more for PH balance running lights opposite the DT. It does reduce some nitrates but I dose PNS probio also which is a natural bacteria supplement that reduces nitrates also. I stay consistent now around 10ppm.
Again though unless you are running a really oversized fuge don't expect nutrrient export miracles. Just sharing my experience. As far as pods, yes they like the fuge to but certainly not enough of a farm to keep the DT stocked up with pod eating fish. My wrasses ate em all.
I have rubble in mine. I think to be really effective maybe 1/3 of the tank size to really naturally control nutrients export and create the pod population you want. Here is mine which is small but grows cheato like crazy.
Neptune gro which I highly recommend but may be to small for your 22g
It works great and is really adjustable just not sure if the spread will meet your size need?
They are worth it. Well constructed and my chaeto grows huge.
