From what I've read and experienced, there is a lot of
mumbo jumbo and
junk science connected with advertising of protein skimmers.The skimmer manufacturers provide ratings for their products, based on recommnended gph fed to the skimmer. Usually the ratings are exaggerated. :frog: In other words, if manufacturer "X" says his skimmer will handle systems up to 300G, it's probably good for a 200G system.
It's kinda like those miles per gallon claims from the car manufacturers...
Octopus external skimmers I owned recommended a feed pump rated at one and a half times the water volume of the system. A 200G system would need a 300gph feed pump. Due to uncertain head loss in plumbing, I always selected a pump on the high side and just throttled it back if necessary.
Internal skimmers sometimes use the same pump to feed the skimmer and chop the water. I have little experience with these.
The air capacity of the skimmer is determined by what type venturi and/or needlewheel the manufacturer uses. These are the devices that the pump uses to "chop" saltwater into a fine bubbly froth. Not all systems are created equal. All skimmers will make bubbles, but if it looks like the head on your favorite malt beverage, you've probably got a good thing going.
Tell us what size system (total water volume) you have and I'll wager there will be lots of suggestions offered for you. I know if a real good quality smikker that's for sale down in your neck of the woods (if it's still available) :idea:
LL