Aquarium vs pond turnover rates

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Jul 9, 2021
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Hello! I've been keeping aquariums for over 10 years and just now starting outdoor ponds..finally XD
A lot of similarities obviously but I've run into a surprising difference. A healthy fresheater aquarium could be have a turnover rate anywhere between 5 and 10 times per hour. Where everything im finding about ponds says turnover between .5 and 2 times per hour.
Can someone please explain the difference to me?

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As a general rule (because individual situations will vary), ponds need sufficient flow to keep suspended particulate from settling out in pipe work BUT do not want to raise the water velocity because they want the particulate to drop out once the filter is reached.

Higher flow rates will simply create finer sized dirt that makes it much harder and more expensive to filter out.

A well designed pond is much more advanced than a simple glass box and there is a lot we could learn from ponds.
 
There are a number of factors in play here.
One could be simple economics.
Convincing the public to buy and pay the bill on a 3000 gph pump may scare people away from running a pond Not so good for the pond business).
Water clarity in a pond is generally not as crital as in a glass box, so if the aesthetic value of filtration is the goal, less may be deemed enough.
If the actual value of water quality is taken into account (as opposed to simple aethsetics.
A good majority of ponds are fairly heavily planted with plant species that are heavy feeder like lilies, or hyacinth, and the plant to fish ratio, and use of those plants improves improves water quality by leaps and bounds.
I had an @ 500 gal pond in Milwaukee, and used a 2400 GPH pump, running a protein skimmer as filtration, it was sufficiently planted so that along with filtration nitrates remained low, and lightly stocked with fish (a few goldfish, and 2 small koi.
I based my water quality on testing, as opposed to simple looks.
koi pond fractionation
below goldfish spawning, koi eating the eggs as fast as they are laid.
GOPR6064
 
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With an outdoor pond, natural algae or plant growth and volume of water to fish load would be some common differences. In a natural pond, natural substrate, substrate and microbe community would be different from a typical tank.
 
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below goldfish spawning, koi eating the eggs as fast as they are laid.
GOPR6064
Bahaha poor goldies! "Excuse us Mr koi, were trying to do a thing!"
Healthy looking fish!

Thanks everyone this all makes sense, especially the aesthetic value. I swear by planted tanks whenever possible, yet I'm surprised they make that much difference in the pond. Maybe because they have natural photosynthesis with a more aggressive growing cycle.

I also thought of the microbes and bugs, but i decided if anything it seems they would create more waste, I could be wrong. I'm building my second pond right now and plan to seed it just as I did the first one. With a jar of mud from a local river. I live in the mountains and the water is pretty clean/healthy. Im sure some people think it's a bad idea but the creek has had a few years to balance out, I see more positives then risks.

Thank you all! And it's nice to be back to MFK after 10 years, thank you for the comunity and quick responses! So much I get to learn with these ponds, I'm sure I'll be back! Haha
 
Suggest you visit some KOI forums if you want some serious pond filtration and plant advice. Keeping large fish in clear pristine water exposed to sunlight is exceedingly difficult.

The slope and diameter of drainage pipework, optimum flow, location and number of bottom drains, tangential returns, use of drum filters, etc. Also good for equipment recommendations.
 
I neither aerate nor filter. Water gets clear enough to see week old Jack Dempsey free swimmers crawling the bottom 2 feet below the surface- underneath there parents when the sun is right.

I have another vat with apistogrammas and I see them more than the ones in the house in glass tanks.

55B183CA-1613-4BF9-82EB-D06782459671.jpeg
 
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