I am also curious about the gallon. I think you have a lot more than you think if the measurments are correct. Also, for that size pond, I doubt one bottom drain is enough. I would have suggested at least 3. It is usually best for each drain (or skimmer) to have it's own filter system and settling tank because it is difficult to regulate the flow, ensuring that each source is flowing enough water. For the sake of discussion, lets assume that the volume is correct and you only have one bottom drain. To answer your question: If I understand correctly, you plan to have one bottom drain gravity feeding the settling tank. You also plan to have a pump feeding the settling tank from the skimmer. The settling tank water will gravity feed to a filter, and then pump from the filter back to the pond. Correct? The problem I see with that is the skimmer line. If the skimmer line could be gravity fed too, then this set up could work just fine. You would need a ball valve on each line to regulate the flow. Pump feeding a settling tank is risky. If the incoming water is pumped out at a slower rate then the filter can handle, the settling chamber will overflow and you will lose water. If the skimmer pump is feeding too much, then the drain line will not be feeding enough. If you need to pump feed the skimmer, plan on putting it on a separate filtration system. You could use a 1/15 hp W.lim pump which flows about 3000 gph on the skimmer line. If you can install a 4" drain line in the bottom of the skimmer box and gravity feed a filter for the skimmer, the system will be much easier to manage. You will love W.lim pumps....they are great! They can also run dry for over 20 hours with no damage, as I discovered by accident one day. LOL! Cindy

I did it! =] I was near tears when I came inside at dark-thirty last night. I asked myself how could something I enjoy so much make me so miserable and it hit me like a ton of rocks, lol. I was trying to create hubby's vision - not mine. And really, just the thought of tryin to get in his head is beyond scary, lol. Sooo...I was at the pond at 6:30 am, coffee in hand. I ripped out the mess, peeled back the liner & started on MY vision. Two hours later I was contentedly sipping my second cuppa joe admiring my work when hubs appears. Wow, he says, that's awesome! Did you do that??? Didn't know whether do laugh or cry. *chuckle* I spent the rest of the day adding fill dirt & top soil & planting the stuff I potted up to make room for the addition. Got the trench dug for my water line from the lower pond to the skippy which hopefully will go in tomorrow. Now if I can just put the brakes on hub's [armchair quarterback] enthusiasm. He's impatient to get the 3 ponds flowing together. Buttttt...my lower pond is crystal clear & the 2 additions are in full bloom...algae bloom, that is. I had to threaten him with a shovel to stop him from draining them to get rid of the algae, arghhh! Ah well...this too shall pass. I have a brand new waterfall/stream that doesn't look half bad. Nothing can stop me now, lol. I am a ponder! *grin* Couldn't have done it without y'all & your collective expertise...many thanks. I'll post pics of my humble lil watering hole as soon as it's up & running. Now I can get back to planning The Big One. Maybe next year.. blessings all around, digger

The adventures in concrete continue. I figured out that there is indeed an overflow pipe. It'll need some attention, though, because it's metal and pretty rusted. I've thought about putting a PVC pipe over it as a sleeve -- both to back it up for its eventual failure and to adjust the depth of the pond deeper. But that's taking a back seat to the concrete. Oh, the concrete. So, yes, it's amazing that it wasn't leaking more when we first got into the house. I started picking at some spots in the interior that looked like they were about flake off anyway. Which revealed a patchwork of patches. Chipping away some more revealed layers of paints (thoroseal?), roofing tar (?!), more thin layers of concrete, fiberglass, more tar with gravel...got it all down to a layer that wouldn't come off with a cold chisel and hammer. Ow...my back. I'm soon to the point of finding a way to make it hold water again. I'm coming around to the thought that further layers of concrete covered with "goop" might not be a great idea. I'd like to find a way to put a liner in it, but there are some really large edge rocks that are mortared in that hang over, that would be over the water line. I'll post a picture when I get closer to addressing that issue. I've spent some time pulling out the intake lines and shoring up the "pump house." Turns out, the half-assed mortared walls fell apart as soon as I took the large rock roof off. Holy cow...I had my head under that thing when I took the old pump out! Here's the new set up, with a new bulkhead pipe, extension of the pipe to the waterfall, new electrical outlet and concrete floor: I had to extend the water line that runs up to the waterfall and used a rubber coupling on the existing ABS line to extend it with PVC. Thought about concreting it in (to shore up the pond wall and surrounding embankment), but I think I'll wait until I get a pump attached to make sure it works. I'll soon start trying to make it hold water. I think I've learned the lesson that more layers of concrete might not be a great idea. Putting a liner might be the right call. There will be challenges with some big overhanging edge rocks that cemented in. The liner could go 'over' them, but I wonder if there's a way to tuck the liner in under the edge and have it stay put?

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.