What Filters Do I Need?

[Meyer Jordan]

If you are speaking of the 3D model in AutoCAD, I totally agree. That was created only as a learning experience and to maintain my skill set as an engineer. For all practical purposes, as far as the build is concerned, a hand sketch of the layout and hand sketches of a few cross sections would be entirely sufficient IMO. Even my rough approximation of the volume earlier in this thread, as convoluted as it is, was off by less than 10%. Hope I didn't leave too many of you scratching your heads.

If you think I am over-engineering this in any other way, please elaborate. Thanks.

Just some quick observations.

1. Your total water capacity is not 1,000 gallons. Since all three (3) ponds are connected, your total water volume is the sum of the capacity of all the ponds plus the transient water in the stream. You are likely much closer to 2,000 gallons total.
2. Your skimmer is in the wrong location for maximizing skimming action and water mixing. See the below edits made to your diagram.

3. Your proposed pond is not a dedicated Koi pond but more accurately a hybrid system. While a vortex chamber or settlement tank may be of benefit, the use of a sieve is not practical for your configuration. The stream will accumulate all forms of organic matter and ultimately transfer that to the main pond basin. A sieve will be quickly and continuously overloaded. You may succeed in maintaining fairly clear water but it will never be 'gin clear'.
4. Size your biological filtration by the projected ultimate fish mass plus the turtle. The flow rate generated by your pump(s) should be at least 1.5 - 2.0 times the total water volume.
5. Your goal should be to have a system that provides ultimate water quality (not necessarily clarity) and will involve the minimum in on-going maintenance. The more 'bells and whistles' added to a system the higher the required maintenance.

 

[MitchM]

The TRP, BOTTOM DRAIN AND SKIMMER are great, but I wouldn't bother with the PREVAILING WIND, it's probably overkill in a pond that size.

Being aware of how exposed the pond is to wind will help determine pond heat loss values, fwiw.

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[sburtchin]

1. Your total water capacity is not 1,000 gallons. . . .

1) Using the minimum cross sections required for a flow rate of 500 gph, the stream + 2 small ponds would be approximately 140 gal. Practically, there will be irregularities and some ground water flow too. If the flow rate is increased to 2000 gph and you add in the water volume of filtering tanks, then the total volume could approach 2000 gal.

Most of the criticism here has been with the volume of the pond being too small, and the deep water area being too small. There hasn't been any further comments about whether the expanded deep water area is still too small, or if it is now adequate with all the intermediate depth plant shelves eliminated.

2) The skimmer could possibly be located as indicated in the revised graphic. I haven't yet investigated exactly how much space is needed, but to give you an idea of the available space there, the dashed magenta circle that slightly overlaps the concrete support rim for the liner is 20" diameter. The concern I still have for that location is that food might quickly get sucked into the skimmer, and also, the fish might want to follow it.


3) OK. Sieve is out. The commercial ones were definitely way more than I wanted to spend anyway.

4) Are you suggesting 3000 to 4000 gph as a minimum? I thought the minimum recommended turnover rate for the pond volume was once every 2 hours.

5) 'Minimum of ongoing maintenance' is paramount. As long as I can make out shapes on the bottom, that's clear enough. Would streams and waterfalls be considered as 'bells and whistles'? I thought the stream would provide additional biological filtration, and keep oxygen levels high.

 

[MitchM]

1) Using the minimum cross sections required for a flow rate of 500 gph, the stream + 2 small ponds would be approximately 140 gal. Practically, there will be irregularities and some ground water flow too. If the flow rate is increased to 2000 gph and you add in the water volume of filtering tanks, then the total volume could approach 2000 gal.

Most of the criticism here has been with the volume of the pond being too small, and the deep water area being too small. There hasn't been any further comments about whether the expanded deep water area is still too small, or if it is now adequate with all the intermediate depth plant shelves eliminated.

...
5) 'Minimum of ongoing maintenance' is paramount. As long as I can make out shapes on the bottom, that's clear enough. Would streams and waterfalls be considered as 'bells and whistles'? I thought the stream would provide additional biological filtration, and keep oxygen levels high.

There are too many variables involved that you cannot control when designing a pond.
I appreciate the desire for minimal mantenance, so you want to strike a balance between efficient detritus removal, sufficient water oxygenation and a stress free environment for your fish without turning the pond into a washing machine.
Some fish are going to be skittish and require quiet places to hide, some areas of your pond will accumulate detritus and extra algae growth, sometimes the water appearance will fluctuate and you'll see periodic algae blooms.
How and what you feed your fish will have an effect, what and how much exterior organic matter will enter the pond will have an effect, how much sunlight hits the pond will have an effect.
Streams, waterfall and filters are great, but keep in mind that if half of your pond water volume is tied up in those features, the pond life may do fine during times when you have them all running but during the winter the pond water volume will be cut in half. That could lead to fish deaths if there are too many fish for what previously seemed like a smooth running pond.
Whether or not the bottom area is large enough depends on how heavily you stock your pond with fish. I would stock it very lightly until you have the pond running for a couple of years. Otherwise you could be setting yourself up for unnecessary difficulties.

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[Meyer Jordan]

1) Using the minimum cross sections required for a flow rate of 500 gph, the stream + 2 small ponds would be approximately 140 gal. Practically, there will be irregularities and some ground water flow too. If the flow rate is increased to 2000 gph and you add in the water volume of filtering tanks, then the total volume could approach 2000 gal.

A 550 gph pump, after head loss, is more likely to result in a 'leaky faucet' flow than anything resembling a waterfall. A 1/4" deep flow over a weir requires a flow rate of 100 gph per 1 inch of weir width i.e.12 inch weir = 1200 gph.

Most of the criticism here has been with the volume of the pond being too small, and the deep water area being too small. There hasn't been any further comments about whether the expanded deep water area is still too small, or if it is now adequate with all the intermediate depth plant shelves eliminated.

As has been stated by others, deep water area and even pond volume should be dictated by a set maximum ceiling of total fish mass.

2) The skimmer could possibly be located as indicated in the revised graphic. The concern I still have for that location is that food might quickly get sucked into the skimmer, and also, the fish might want to follow it.

Change the feeding location.

4) Are you suggesting 3000 to 4000 gph as a minimum? I thought the minimum recommended turnover rate for the pond volume was once every 2 hours.

Yes. Minimum recommended turn-over rate is 1.5 - 2 times per hour.

'Minimum of ongoing maintenance' is paramount. As long as I can make out shapes on the bottom, that's clear enough. Would streams and waterfalls be considered as 'bells and whistles'? I thought the stream would provide additional biological filtration, and keep oxygen levels high.

IMO 'bells and whistles' are devices and treatments that are totally unnecessary and have no natural counterpart and are more to achieve an aesthetic goal than supporting the health and balance of any habitat-aquatic or terrestrial. A waterfall and stream do not fall under this description.

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