My pond is about 1800 gallons. I designed and dug it myself. I use a submersible pump. I wish it was out of the pond, and here is why: I have to enclose the pump in a filter "sock", to keep debris out. That filter periodically needs to be washed off, which means raising the pump and attached, bulky hose, opening the bag and hosing off the filter material. Then reassemble and replace. I have to perch on the side of my pond to reach the pump and in the middle of summer with everything growing and rocks slippery, well, it isn't ideal. Maybe it's bad design on my part, but I find it cumbersome to maintain. I did it this way to keep expenses down, and it certainly is quiet, and hidden. And it works quite well. I just don't like the upkeep. If I had the option of a contractor installing it, I would request the easiest upkeep method and pick the pump for energy efficiency. There is a big difference between pumps as to how much energy they draw. Do your homework there. Hope that helps-

I don't do too much filtering and can't help re total volume, I guess I don't even understand what or how a 'bubble pump' would filter, but I can help with the connection. You can find almost anything you might need at a hardware store, or Lowes/Home Depot although perhaps not completely together. The issue you didn't mention is controling the flow to the spitter. After the T you will need a shut off valve on the way to the spitter that you will turn part way off until flow is correct. The pump connections will depend on your pump/ waterfall, and spitter locations. That wasn't clear. Presumably this is all flexable tubing and if so then you will just need a connector with female thread to 3/4 barbed tubing fitting. These are usually found near the pvc pipe and fitting section. You will also find 3/4 tubing T fittings there too. These tubing fittings get jammed into the tubing. Usually you warm the tubing in hot water to make it soft enough to push the fitting in. You will probably need extra and different fittings to connect the shut off to the tubing. If you already have a shut off in the spitter line then neverrr mind.

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

Thanks Mike. I suspected as much. The manual that came with my pump says its a Sequel 750 series 4250SQL13 but I can't find a picture of it on the MDM site. It looks more like the Sequence 1000 series pumps as is that color. The newer Sequels are bronze colored--mine is black. I bought it in 2006 so I think it was a older model of the new Sequel pumps which have 3 variable speed impellers. It's a 1/8hp motor runs on max 175Watts. According to the pump flow curve at 8ft of head it should be pumping 2500GPH, at 5 ft about 3200. Havn't had a problem with the flow now that I added a midwater drain to my sc and running only this pump on the sc. Would you recommend that I pull the pump now and have the bearings checked or wait until the end of Oct (end of our season). With the pump house covers on I can't hear the pump but will check it regularly. Don't want to burn out the motor! As for arcing breakers--had them installed in my house last fall when doing renovations. It's code here now and the inspector won't pass if not installed for bedrooms. Mine have a yellow sticker on them and a yellow test button like the GFC plug (except that is red). They are expensive--something like $120CD each. The GFC breaker has blue switches compared to the black on the normal breakers. They are also expensive. When I did the reno's on my kitchen, livingroom and bathroom upstairs installed new wiring as the old stuff was only 2 prong. Kitchen plugs near the sink have to have GFC plug and a GFCbreaker on the line. My pond plug has the GFC plug and a breaker but it was mistakenly wired to the same circuit as the furnace which is maybe why the breaker was put in. Thanks for your help. Patti