We have about the same size system as you, Chris, & Cliff/Joann, 2500 glns, 12 ft. head, not quite as long a run, although we use a skimmer with a small filter, not the bottom drain. Our falls drop the water into a steam bed near an upper pool, then water falls over a dividing falls between the small upper pool and the larger lower pool. The skimmer housing located at the end of the water's run (lower pool) has the pump in the bottom. The only way I've ever seen it done was to PUSH water from the pump up to the Bio-Filter. We didn't use a stand alone prefilter because we just didn't think both a mechanical filter and a bio-filter, a stand-alone bio-filter, was necessary, especially with no koi planned. IMO if you are using a bio-mech filter wouldn't you want to go with the manufacturers recommendation on sizing and pumping through it? I would think there might be an issue or two with how well it filters if you pump to fast or too slow; I could see there being a wide range available though (re: flow rate). We use an Atlantic 1500 BF (wish it was bigger) has plenty of room for the filter media at the bottom where the water typically enters the open-air chamber. Our bare-root and gravel-filled meshpots go on top of the filter media. We actually have two pumps in our skimmer box: one goes to the bio-falls; the other one goes to a discharge pipe right below the weir and creates a rapids effect... gives us a way of changing up the rate of water into our stream bed by turning on and off the rapids pump.

So many nay-sayers! All it takes is a large pocket book, (preferably inexaustable public funding)and a panel of experts to create a "natural enclosure". Ask your most local zoo! My opinion is it could be done, and with appropriate habitats for different species, BUT, it would be expensive and have to be large enough to provide room for the transition of habitats. You would also be adding LARGE amounts of risk to your pets. Predators, parasites, pathogens, and other microorganisms that you would have no control over. Your pets would also have no defense against them, (other than their shell) as they are not indigenous to your area. None the less, you "could do it". You would have to create a large sump either covered, or separated outside the perimeter of the enclosure. My first thought is a shallow stream, where a slow moving, (but enough flow to carry waste away) stream would drain into your sump area through a screen too small for your smallest pet to get through. (Maybe large holes cut into the side of a 55 gallon drum in a grid pattern.) That sump would need to be AT LEAST a 100 gallons, (not necessarily all in one container), and contain a prefilter, mechanical filter, and bio filter to treat your tortoise wastes. Since they would use it infrequently, (after all, they are tortoises)it would probably work fine to treat the water so long as it could get enough time to chemically breakdown, and balance. Your prefilter could be as simple as a mat of plant roots near the drain to the sump, or a settling chamber, which would also pre-treat the waste, while allowing the dirty water to flow through. Properly chosen, the plants would also provide a food source. You would pump from the sump, beyond all the filters, back up to the head of the stream area, and the water would carry wastes back to the sump through the drain system. Experimentation would be needed to set the water flow, then it would have to be adjusted as the plant growth varied. The automatic requirement is the most interesting part of your idea. THAT could get very expensive! Filter back washing to waste, chemical monitoring, water level, etc. is quite a design feat in itself! But if you are willing to monitor the water level, and run a hose a little every few days/weeks, it would not be too bad to have it manually operated. In fact the bigger the sump, and filters, the less attention it should need if designed right. A simple toilet valve could control water level for you, but the supporting infrastructure becomes an issue. Solar pumps are certainly available to move the amount of water you need to move, and most likely, move it often enough to keep the water healthy, depending on system loads. (size of pond exposed to sun, wind, and relative filter sizes, how many leaves get in, etc.) Just like your pets, water features need attention. So you know, there is no such thing as a maintenance free pond, just one that hasn't been maintained, or is not yet completely full of stuff. Nature puts things in, we take them out. We do this to keep the area a pond. In nature, the pond is always changing, and always filling with gunk, getting shallower and shallower all the time. What you proposed is certainly not a simple project. What other proposed is simpler and more practical. It certainly is cheaper, and less risky to use a large saucer, and unless you are willing to create a large water sump, a lot less headaches! You have easy control over the quality and quantity of the water in the saucer, and simple disinfection with a weak bleach solution provides a micro guard. When you decided to take on pets, you decided to devote a portion of your life to their care. If you want them to live in a natural area, you will need to return them to their native lands and set them free. Other than that, continue to care for them daily. They deserve your attention! And you benefit from providing for them. Heck, they're tortoises, you only have about 25-100 years to take care of them! Buck up! -TT

I have a number of ponds and water features in my yard from 2 1000gal ponds dug in-ground with liners to the simple fountain pond. For that I took 2x12's and made a box 4'x4'. Took a liner remnant and lined it with that and stapled the liner to the top of the wood and covered that with a lip of molding. I have an old fountain I set on a cement block so the fountain cleared the water level. Stuck in a pump, stained the wood and, in one afternoon, I had a cute little pond. I stuck in some plants and put it up near the house so I can hear the splash of the water. My dog thinks it's her water bowl and, occasionally, on hot days, I will find her laying in the pond with the fountain splashing on her head! We both love it and it was cheap and quick to make with no digging! A side comment: I put a few goldfish in the fountain pond for the grandkids and forgot about them. I turned off the pump for winter and the pond froze over. Imagine my suprise when the pond thawed this spring when I saw those goldies happily swimming around. This in a foot of water in zone 5!

I have used fountains in my pond(s), but on a much smaller scale. I think smaller fountains and waterfalls and streams are more common in the home ponds you see on here. The type of large scale fountain you seem to be talking about is very pretty, but I have only seen it near me in front of more commercial buildings. I have seen it in front of an upscale apt complex near the entrance, and in front of a commercial building with professional landscaping. While there are all kinds of ponds, most here seem to have fish and/or be water gardens, and people like to see the fish. I have small ponds so I have only ever used a small multi tier fountain nozzle and a "bubbler" fountain. Spray leaving the pond from the wind is always an issue. So for that reason only, I would consider going with the smaller one. Because if you find the wind blowing the spray out of your pond, it will drain your pond and make upkeep difficult. Since you can't return it, that would be a waste of money. That is another reason people with smaller ponds probably don't use them a lot. And most "backyard" ponds are probably smaller than yours.