So if you are just beginning this saga, the precursor threads are:
Here
AND
Here
In a nutshell, we hired a local company to build our pond and they failed at it. They are honoring their warranty on craftsmanship and we are taking advantage of that to correct our mistake on size (we wanted 5000 and it was more like 3000 due to dimensions we gave them) and doing a much more robust filtering implementation.
So the point of this thread is to brainstorm with the experts here and come up with a solid plan before they do ANY more work.
You can see pictures of the original build
here
So here's what we are starting with. We want to increase the volume of the pond to 5000 gallons. Because of the sewer line running parallel to the pond, the only direction we can go is longer. Luckily there is room and adding 5 feet to each side would give us that volume. I think this would also merit adding a second skimmer (one on each narrow side) to handle the surface area.
I am struggling on how to do the water return, though. I would love to bring it up in the center and then we can either do a fountain or jets or both, but I am also considering just a couple of side jets. I am also wondering if a 24' long pond would require two bottom drains.
As this is a rectangular pond, 4 returns, one in each corner would be in order and yes, at that length 2 aerated bottom drains are definitely in order.
As for filtering, we want to go ahead and keep the Challenger pallet and use it on the skimmers. The bottom drains will go to a gravity fed separator and then mechanical filtration of some sort. That part we still need to decide upon.
Okay, the pallet filter would work great on a skimmer circuit, especially with two skimmers, both valved independently to control the flow from each. With two 4" bottom drains, gravity fed, I would highly recommend the UltraSieve III. This easily handles two bottom drains with a max flow rate of 7900gph! You mention mechanical filtration, but no bio filtration. Your Challenger will handle your mechanical fines filtration just fine. For bio, you could install one of Zac's custom shower units. It can be configured in several different ways for providing return of the filtered water to the pond. This should provide you with a very efficient system.
So that's our current goal. These koi are our family, not "just fish", trophies, or inventory. We want them to have a good home to live in, room to grow, and something attractive to be a centerpiece for our landscaping.
Basic Starting Specifications:
Desired Volume: ~5000 gals
Estimated Interior Dimensions: 24' x 6.5' with a depth of 5' (can vary , but must meet volume)
how about 20'x6.5'x 6'total depth = 5850gal! Even better!!!
Reinforced Cinder Block Wall construction with a 16" footer
How thick? I'd suggest min. 6"thick with double course of #3 rebar!
40 mil EPDM rubber liner with backing material
Flagstone finish with smooth interior edges
For the coping, you could use a stone called "Three Rivers tumbled" which doesn't have the sharp jagged edges
2 Skimmer units integrated into the pond walls on the short sides
Yes
Will use existing Challenger 50 pallet to operate skimmers
Yes
Something for the bottom drain(s?)
Two 4" aerated KoiToilet I bottom drain units
Something for aeration.