I think th OP is referring to the seperate feed pump that supplies tank water to th eskimmer.
What size tank is this going on? THe recommended flowthrough is 1.5-2 times you system volume per hour through the skimmer....However, If this is for you 125g system in your sig line the 110 is too small a skimmer!
No problem here....I run a HOB overflow that has 2 1" standpipes on it...1 standpipe is free flowing to the sump, the other standpipe runs to the skimmer with a valve to control flow. the water level above the standpipe that goes to the skimmer is at a constant level so the flow is constant.