Hi Dennis, believe it or not I am using a Mag 12. Water pumps out same way as internal (straight up) but then I have a 90 with tubing running out through the side of the stand with the skimmer sitting outside. The return goes back through the side of the stand and into a bulkhead in the sump.
There should be no difference running internal or external except maybe more pump options and therefore possibly different performance levels due to the flow rates with those pumps.
I can tell you that I have been playing around with the MTC skimmer using a Blueline 30 and 40 and you so hear them. They are not loud but compared to a Mag pump which you don't hear anything, there is the fan noise.
I don't think there is any reason to switch locations unless you need the sump space.
As Jeff said to me, the skimmer doesn't know if the skimmer is inside or outside.
There should be no difference running internal or external except maybe more pump options and therefore possibly different performance levels due to the flow rates with those pumps.
I can tell you that I have been playing around with the MTC skimmer using a Blueline 30 and 40 and you so hear them. They are not loud but compared to a Mag pump which you don't hear anything, there is the fan noise.
I don't think there is any reason to switch locations unless you need the sump space.
As Jeff said to me, the skimmer doesn't know if the skimmer is inside or outside.