weird noise from power steering

well I filled up the reservoir with the fluid and after rotating the steering wheel left to right a couple of times the sound went away but my question is do I now go ahead and fill it again if it reads low. I filled it to max and then worked it in and now it is low. maybe it was really low and I need to put more in to fill the reservoir. What should I do?

i had a problem like this is my sonata. AFter the second refill i took it to the dealer and they found a leaking seal. They had to replace the entire steering rack to fix it. problem solved though.