Joecd, a very important question is how will the water get from your pump to the bog's and waterfall? Is your pump in the skimmer? If not how does it get from the skimmer to the pump? Most important is what size pipe are you using?? My point is, no matter how big your pump is the amount of water you can move is limited by the size of pipe, the head (how many feet of pipe, how many fittings and how high above pond level).

I used a Savio skimmer with 16" opening and found that it would not keep up with the 6k GPH pump (in the skimmer), especially if I left the skimmer filter pad in place. I finally removed the pad and replaced it with 2 layers of 1/4" hardware cloth which helped but only if they were cleaned frequently.

In a pond that size you should have a bottom drain if you will be keeping Koi or Goldfish. I say this because a skimmer is only effective at cleaning the top of the water. All the fish poo and other sinking debris will not get filtered unless you have a bottom drain. The number and size of your fish will effect how much filtration you will need and how often you will need to "turn the water over".

Are you planning to use the bogs for filtration? If so how big are they and how will they be constructed? Be aware that bogs are a great filter if they are big enough and you have a way to keep them clean other than removing all the gravel. Bogs used for filters in ponds with fish are notorious for clogging up and becoming harbors for harmful bacteria. Do some research on bog filters before you decide to use them. Water garden people who keep fish in their water gardens use them a lot but most koi pond people will not use them at all. Just my two cents worth. I'm sure others will provide input as well.

Thank you for your time. I have a 16 inch savio skimmer and a 6000 + savio pump. Pump is in skimmer. I am using 2 inch pipe. I was going to design one bog by T-ing off the 2 inch line and build a 3 x 4 foot bog with a 2 inch PVC piping with saw cuts going perpendicular with pipe every 2 inches with a clean-out coming up to surface. One pipe only across the middle. My waterfall bog is already designed as a bog which fills from bottom that will have a 2 1/2 foot lift maybe more like a 3 foot lift from a bottom of skimmer. This one is also about 3 x 4 foot and also being fed with a 2 inch flexible PVC. I have 4 kids and I am trying to accommodate all w a large variety of fish, turtles and plants. I really don't feel comfortable putting in bottom drain for reasons of failure. I was planning on siphoning/ vacuum as needed for bottom debris.Is 4 foot to deep? My original concern was if i was going to get proper circulation with just a skimmer/waterfall set up? I don't really want to add this mid/bottom flow piping off my skimmer because if i ever have skimmer problems i will have to deal with this pipe attachment through my liner which also brings me back to a potential leak! If my skimmer doesn't keep up what will happen? I really do appreciate this info. I have read many books and I am going to start building on August 6, 2013.