I also remember you mammabird. I usually don't use the forum much in the winter but come back on in the spring just to catch up on what's new etc. I have a retrofit bd as well mine is some modifications on the Tetra through the liner drain (which froze) but I used the cap from it for my drain. I am replacing that this year with the Aqua Art Drain as it sits flatter than mine. Not sure if I understand your "hump" but you usually put the bd in the deepest part of the pond. Avid koi-keepers like to do TPR's--but that also means cutting a hole in the liner. With your pond dimensions you might want two bottom drains one for each deep section. That would mean two bulk heads (I did pipe boot connections) through the liner on the side of the pond wall nearest your settling chamber. My drain has a 4" line reduced to 3" just before it enters the sc followed by a 3" knife valve (there much cheaper!). I take my drain out for winter because of my climate. Water inside pipes in my climate not a good idea. My settling chamber is a liner chamber (kinda like a pond beside the pond)350 gals-my pond is 2500 gals. They say sc should hold at least 10% of your pond volume. I really like this system as use sc for water changes. I have 3-4 ft square matala mats in my chamber which is also my mechanical filitration. Good luck with your new pond and move. Patti

Dorothy, I know exactly what you mean about wanting it to look natural and fit in. Unfortunately, no matter how much planning you do, it's probably going to looked "plunked down" for a while, until the plantings fill in and it gets that settled look. In a year or two it will be better than you ever expected... People have given great ideas already, but I would agree with the suggestions to take your time and look at every pond/water garden magazine, book, website and tour you possibly can. And take any advise Cliff and Joann have to offer--one look at the pics of their pond and you'll see why. Missa7's idea about water coming up out of the ground is one that we used when building our pond. I didn't want any pipes, etc. showing (even in the winter when there wasn't any plant cover) and I didn't think water pouring out from under a pile of rocks would look natural either. Those were some of the reasons we decided to put in a bog-type gravel filter (shown below). It's not very visable, but the hollow log on the right side of the photo is where the intake hose for the bog is. The water flows up through the gravel and overflows into our big pond via both a stream and a small waterfall. We were lucky in that we actually have a bit of a slope in our middle-of-kansas yard so we didn't have to pile up dirt to make a waterfall. Below are two pictures of ponds that I think do a great job of adding waterfalls "gracefully" in what looks like relatively flat terrain. I have no idea whose ponds they are, but I wish I did so I could go visit! :-) Have fun coming up with ideas! Sherry

I did pipe boot connections on my retrodrain through the wall of the pond. Didn't make my hole as large as what Horton suggested--only 1/2 the diameter of whatever size pipe. Most recent was 3" and made a 1 1/2" hole in the centre of where I wanted the pipe. The liner stretches but it takes strong fingers. Easy to do and as far as I know no leaks. Curious why aren't you looking at external pumps for your pond? They are more energy efficient, easy to winterize. I have a priming pot on both of mine even though they are below ground but had a problem with quilt batting getting wrapped around the impeller of the older pump before using a priming pot. I have a Sequel 4350GPH pump that is very quiet uses 175W. This year I plumbed this pump to my sc and the old pump (Sequence 750 4200GPH but only pumping about 1/2 of that due to bent shaft) to my skimmer. I probably don't need both pumps as also changed my waterfall out this year so is smaller. The Sequence is noisy and leaks a little on start up around the shaft. Long story short I love the external pumps. Aquaart carries good external pumps and also the bottom drain that is mentioned either here or other forums. I also like the skimmer--it collects alot of surface stuff like dust! In the fall I run my pond on the skimmer only so that I can remove my drains (have a midwater drain now which is also awesome) before the water gets too cold. Like Horton my pumps/sc are hidden under a deck. Two pummps might be an idea for your pond as you need less flow through your biofilter and more flow through your waterfall. One idea I saw here if you only use one pump and need the circulation (in your case at least 5000GPH) was to pump part of the water back into the main pond and the rest through the biofilter/stream. Aquaart has a diagram of how to do this. As for valves depends on if you have a drain on you skippy filter etc. I have a knife valve between pond and sc on the bd but on the midwater drain which also goes into sc I don''t--I use a standpipe. After skimmer and sc 2" ball valves--I know could have used knife valves there but ball valves are more reliable. My check valves are after the pump but before the ball valves to the waterfall filters. This is to keep the water from the waterfall filters coming back down through the pump and into the pond if power goes off which it does here frequently. Because I have priming pots, sc and skimmer I don't need check valve before the pump. Can't remember when you need check valve before the pump--sorry. Ball valves after the check valves to control flow to filters. I know that I could get away with running one pump now due to the changes I made in adding a midwater drain to my sc (had alot of draw down!) and waterfall changes as the valve on my Sequel pump to higher waterfall is turned down more than 1/3rd. It's just time consuming and more pipe to change it out again. I don't know if you are allowed to use ABS in the US. I use it here as fittings are available and it stands up to my climate. Also because it's black any pipework in the pond lie retro bd don't show as much. You have a fun project on your hands! It can get rather overwhelming but there are many knowledgable people on this forum who can help you. Good luck. Patti

Waterfalls are designed to provide aesthetic appeal, some oxygen, and to create a circular motion in the Main Pool to direct floating debris into the skimmer. Falls don't add much O2. Directing pump output directly into the pond creating a current moves more water to the surface where gas exchange happen. Falls only improve gas exchange in the sense that you need moving water to create a fall, it isn't the falls directly. That's just kind of nitpicking in your case because you sure shouldn't have any O2 issues at all. It's only in high fish load ponds that a keeper would rather use a tangential pond return to create a stronger current than have a falls. But a person can improve total gas exchange and still have falls for the same costs. I call this a waterfall catch basin. Installed: The idea is to direct all the water from the falls to the pond bottom which pushes low O2 water at the bottom to the surface where gas exchange happens. It also calms the surface of the water making fish view better. It also catches foam that can be produced by falls that float around the surface. You still get the look and sound. Falls don't really direct stuff to the skimmer (although many web sites say different). Skimmers work because of surface tension. The Helix skimmer can house a submersible pump beneath a single blue matala pad, but it is my understanding that external pumps in flooded suction applications are more energy efficient and last longer being they are not constantly submersed in water. I've never noticed any difference in life span. Some pumps last a month, some seem to last forever. My best lasting pump was a 900 GPH mag drive. Raccoon pulled it out of the skimmer once and I found it laying on the ground the next day still running. Put it back in the pond and it ran fine. Submerged pumps are made to be submerged. A mag drive for example doesn't have any seals to wear out. Energy efficiency I don't think has anything to do with external vs submerged. Pumps vary a lot in that regard. So you can find cases where one or the other wins. Where you really win energy wise is picking the right pump. Low head when appropriate for example. But also the size. ...into one or more plastic drums filled with possibly lava rock and/or a series of matala pads to enhance water quality. This is a really old type filter. There are much better. I would not bother. I don't like cleaning mats, especially when they don't improve the water. I think you'll falling into a trap that I and pretty much every other pond keeper falls into. Laying awake at night dreaming of magnificent filters and clear water? Most filters do nothing, yet many owners will say the reason their water is clear is because of their filter(s). This is especially true in the DIY world. They see what they want to see, that their invention is the best thing ever created. Get yourself a UV filter, installed, sized and maintained correctly and you'll never have green water, 100% of the time. Longer term water can get a little crappy. Water changes takes care of all these causes. In fact, there is a newer type system a few people are using that's based on the oldest fish keeping practice, 24/7 drip water change. A drip emitter runs 24/7 into the pond and an overflow takes away the extra water. IMO there is no better system based on what keepers have long said about normal water changes. If the overflow is directed to landscaping that would normally need water there's no extra water cost. People using this system have also not seen green water but too early to tell if this is always true. My next pond will be 24/7 drip for sure. By running the 3" pipe under the Upper Basin, I can keep the water in it protected from freezing. I don't think pipes can be protected from freezing since ground freezes to some depth and the pipe are above grade at some point I assume. Freezing pipes in ponds aren't generally an issue because they're open to the air. Closing them will valves can create a problem. ...submerged oxygenating plants. They produce O2 only when the sun is out. At night they consume O2. The net result is they are a negative. They're also ever difficult to keep alive. The drums I mentioned are only to be used to cut the discharge velocity to That can be addressed by changing the pump size or simpler ways. If you really want drums then cool. I used to love drums, had them all over the place. I slowly got over the thrill of lots of complex plumbing and started removing stuff. Turned out I didn't need any of it. I'm not saying you shouldn't have complex...it's fun for awhile...you learn a lot...but there are other options. You mentioned two pumps: one for the skimmer at 2000 gph (more or less) and a 2nd one pulling a slip stream directly from the pond, mid-depth. I have a single 20A circuit for power. I agree that I want the weir floating and not being sucked full down and so two pumps might work better, but there would be no filtration for the 6000 gph pump to supply the waterfalls. That concerns me. Why the concern? You mean no pre-filter? External pumps can have a strainer pot before the pump to protect it. But a mid level pickup normally will be pretty clean water. Submerged pumps can be placed so clogging is reduce. Placing them on the bottom is bad imo, get empty the pond. The helix skimmer is rated at 8000 gph and I might be able to use two of them side-by-side with a 4000 gph pump for each. What about that? I personally wouldn't. It would work of course, but then you have 2 skimmers to clean out. Extra $500, extra install time, another thing to go south. I like simple. If you want 8000 GPH for aesthetic you should absolutely have 8000 GPH. Ponds should always be built to want the owner wants...it's the whole point for building a pond. But if this is mainly to create water flow for filtering or driving stuff to the skimmer or because someone said a falls should have 150 GPH per inch then you have options. For example, I had a pond once that was 7600 gals, 6 connected ponds, 2 skimmers, one waterfall, all driven with a single 900 GPH 42 watt pump. The waterfall was 2' wide, but the water sheet was less. Much higher fish load than you, no bio filter. Aesthetics totally aside, this functioned fine technically. Water was clear to 4.5'. It took me awhile (several years) to figure out how it get the water clear (this was before UV filter were cheap), but it is possible with a lot less flow. One thing you might consider for example is making the 3 outer pools into a single pool and maybe going for 1 waterfall. Again, I really don't want to talk you out of your vision...just not sure if aesthetics or technical issues are driving the design. I know it's partly both, but is there room to down size the pump? 8000 GPH for this type of pond is a lot. Which is fine if that's what you want. The plants, the bio filter stuff...if you want all that because you want all that then cool. I love stuff like that. But don't be fooled into thinking this will all give you clear water or make water cleaner or improve fish health. Plants add more waste than they remove in total. There are certain things some plants do remove, like nitrate, which is cool. But with a couple of goldfish you are never, ever going to come remotely close to having a nitrate issue. Plants like the Iris will need to be fertilized, which will add nitrate to the water. Not a problem, but don't believe people that say these kinds of plants remove waste. Waste water treatment plants do use vegetation to reduce some chemicals. But these are huge and nutrient levels very high which they're only trying to knock down. Backyard ponds aren't in that ballpark. Also, you mention that Helix 8200 is a high head pump, I wasn't aware of that. How can you tell? The max head is over 20'. A low head pump the max head will be 10-15'. There are even very low head pump schemes where the max head is an inch or two. You also see the difference when you compare GPH per watt, although pumps vary because of other things. Lower head pumps should be higher GPH per watt, otherwise they're really bad pumps. Lastly, I was not planning on any compressor for subsurface air. I'd prefer to rely on natural oxygenation and purification of the water, if practical. Your pond doesn't come close to ever needing more O2. For comments on the plumbing I'd need a diagram. Text is too hard to follow for that. But in general, I'd just pump directly into the upper pool. Like make 2-3' of total pipe, maybe one 90. Instead of a drum you can just build a rock/block.brick wall inside the pool, on top of the liner...I should draw this.