It’s very easy, I had no clue.
I have a 1 gallon glass bottle in my refugium, with hole in lid for air hose to small air pump.
I purchased nice fresh shipped pods and phytoplankton and filled the bottle 1/2 way, and dosed my algae refugium. Turn on the air, make sure the bottle is in the refugium water and gets light from algae refuge light....and you are good.
Mark side of bottle with sharpie for level, so you can top off any evaporation with RO/DI as needed.
Once a week I pull out a large glass and dose my algae refuge, then I top off the bottle with fresh saltwater mix I use for my water changes.
Fish go crazy and corals get fed their favorite natural treat.
Now you can also seed your friends grow bottles, and top off with fresh saltwater as the pods and plankton grow back really fast it appears.
Good luck.
Note....If reefer experts see I am doing something wrong, please let me know as I am doing a lab experiment here based on instructions from the plankton and algae dealer. Thank you.