jclimber, I've have a setup very similar to what you are talking about though my pond is only half the size, still large for an ornamental pond with goldfish. I have a Savio Skimmer with two pumps, one goes to a rapids effect at a small, small stream that feeds in under the biofilter fall, and, the other one pumps into the biofilter. I also have an upper pool and a lower pool separated by a wide but short water fall. The Savio Skimmer (full size) is located at the other end of the lower pool from the waterfall. My two magdrive pumps work fine. Laguna brand 3900 waterfall pumps. That all said, I would take ccoombs advice, no doubt. The number one problem with my pond is keeping the detritus and other junk off the bottom. In fact, you never can keep it off the bottom. The detritus is so fine that you only stir-it up if you get in to clean the pond. So my advice would be to go with the bottom drain setup but still use a skimmer box for the top floating stuff. Thanks for the btm drn link, ccoombs; I hadn't seen that... and thanks for the explanation of the bottom drain (not for draining, necessarily) because when I first heard about BDs that what I thought for sometime! I like the suggestions for saving money. If you can afford the time, better to make your own... esp. underlayment; I actually think old carpet (go dumpster diving at a carpet store) is superior to the underlayments I've laid hands on. Here's another suggestion: I'd get the rock out. It would be one thing if they were in the water atop the liner, but rolling liner up over them is just taking up space. Plus, you could use those big ones to help landscape at the edge. So it occurred to me when you talked about getting an electrician to bring a circuit out to the pond that this electrician is going to have to pay someone to trench. Most places are under the National Electric Code and that means burying the cable 30" or more... they're going to want to use a trencher. If you're going to have to get a trencher in for that you could save by getting a mini-excavator (rental from any tool/equip rental shop) and have it equipped with multiple bucket sizes... most come with options. get a slender bucket for the trench work, wider bucket for the rock. If an excavator can't lift the rock it should be able to beat on it enough to crack it smaller and scoop it out... of course, you could just pay someone to remove the large rocks. Whatever you decide make sure you have 'em mark the area for underground utilities. I really like your setup though. You never did say if you planned to have fish, what kind? Is that a german sheppard!? He/She will love the pond!

Using an inefficient pump is also a problem in green house gas generation. Just like with our cars, even though 4 or fewer cylinders will get you there comfortably, six and eights are preferred. There really is no good reason, but people buy them anyway. Pond pumps are also able to do the job more efficiently than utility or sump pumps, and are designed for the job they do. You can get there real fast and spend a lot on the gas to do that, or you can get there fast enough, and spend half as much on gas. Same with water pumps. You can spend a lot of money to move the water, or you can spend less. You can risk polluting your water with oil, or you can get a safe pump. Any of the primary options creates bigger problems for the planet. I try to live efficiently. And hope others will too, as it is less expensive personally, and more healthy for everyone in the long run. Being able to afford to do something wrong, doesn't make it right. If you can't find the right way to spend your money, give it to someone that can. Oh, in the interest of full disclosure, I am not perfect, that is god's business. I am simply trying to be excellent! (Though still FAR from that!) I smoke, I drink, I use weed killer, I use bug killer, I drive a car, I have an OLD septic system, I have some incandescent light bulbs, and I have a chlorinated swimming pool. But, I smoke and drink less than I used to. I follow the directions on the killer cans, and use them now as a LAST resort, I drive a car that gets 38 mi/gal, have compact florescents in my most used fixtures, and want to convert the pool to a pond, just couldn't sell the Mrs. on it. Yes, I have a long way to go, but I am better now than ever, and encourage others to try to improve as well. Little bits here and there from everyone, ad up to big bits that are good for everyone. So please, use the most efficient pump you can. -TT -TT

Well, I'll do my usual thing and recommend a DIY skippy filter if you have enough space. Still very pleased with mine, it's into its second year of operation now. I have clear water, and so far NO maintenance or cleaning has been required whatsoever. For me this is a BIG consideration. No dreary filter cleaning... I just enjoy the pond, watching the fish and the teeming life in there. I don't use UV, so no extra on the electricty bills, and no new UV bulbs every year. Skippy's do need to be big compared to commercial filters, but mine is half buried, and forms part of my waterfall return, and is almost entirely hidden by plants and rockery around it, and watercress growing in the top. And it works WAY better than the commercial filter and UV that I had before. Note that although my water is clear, I have a LOT of mature plants in the pond and waterfall return, and about 60% surface coverage from lily pads, frogbit, water hyacinth, water lettuce, duckweed and azolla. This undoubtedly helps. Also, in my design the skippy filter is sitting in a lined "well", a few inches bigger than the skippy itself all around. So filtered water overflows into the well, and then overflows from the well into my waterfall return. ie. the well allows some additional settlement time for anything that gets through the skippy. By the way, the watercress and veggie filter stage (plants in the waterfall return) seem to be working extremely well, because the duckweed and azolla is not as rampant as previous years. Only need to scoop some out once or twice a month.

This will get you in the vicinity of how many gallons in your pond --> https://www.pondvolumecalculator.com/ The basic formula for calculating the volume in gallons of a pond or pool is to use the formula L x W X D x 7.5 where L is the Length in Feet, W is the Width and Feet and D is the Depth in feet. Most ponds are not perfect squares or circles so when you use the pond volume calculator you should make allowances for variations in depth and shape. Try to use averages when you enter the data and when your pond is irregular shaped with depth variations give up to 20% variation to what this calculator shows. What type fish? Probably going to need some type of filtration.