How do I use plants to create a mini-pond ecosystem that doesn't need a filter?

How do we use nature to create a mini pond (less than say, 400 gallons) that doesn't need a fancy filter system to stay healthy?  I'm thinking of a small goldfish pond or patio water garden.

What would this system look like?

How do we choose the right plants?  What climate considerations when choosing the plants?  How do we know how many plants to put in my pond?

What about fish?  Would this help or hurt the system and how do we know how many?

What are other considerations for a self-sufficient water garden or mini pond?  

Where do we start looking for information on this kind of thing?  

I have planted as many deciduous trees and shrubs as I could fit along the south and west of my smallish pond (20,000gal) for summer and afternoon shade. I am particularly excited about the PNW crab apples that can handle wet feet and be grafted to any apple we want, and vine maples for their foliage. These also handle wet feet so their roots will be consuming pond nutrients from the pond’s edge. I also have some big leaf maples planted to the west and south of the pond, which have wonderfully bright green foliage this time of year. They are also great ecological stewards, supporting twice their own biomass in other plant species on their trunks when established . This in turn provides them more water storage and nutrients seeping through the moss, which they root into from their trunks. That was a tangent, but my main point would be deciduous trees and shrubs to the south and west for summer shade to reduce temperature and oxygen fluctuations and evaporation.

We have our first of many Ring of Fire biochar kiln burns tomorrow, and at 400gal of char per burn we hope to accumulate enough to create a biochar based filter with a cascade back to the pond for aeration, using a solar powered pump. My main apprehensions are the possible adverse effects of part time aeration (we would not use are backup diesel generator to power the pump during the dark and rainy season), and the degree of evaporation in the summer from moving the water and increasing its surface area exposed to sun. I have also considered just placing “socks” of biochar out in the pond instead for simplicity.

Won’t you need aeration if you add fish ? I think a small pond is like a large aquarium in that regard ? Otherwise your plants will pull all the O2 ?

I think I always see some sort of water lily type cover plant in koi ponds and some mountain lakes, but I’ve never really studied them so much as just fished around them.

It depends on the plants and the fish.   Some fish do best in stagnant puddles,  some plants oxygenate water.

It's about finding the right combination for the location.

r ranson wrote:How do we use nature to create a mini pond (less than say, 400 gallons) that doesn't need a fancy filter system to stay healthy?  I'm thinking of a small goldfish pond or patio water garden.

What would this system look like?

How do we choose the right plants?  What climate considerations when choosing the plants?  How do we know how many to get?

What about fish?  Would this help or hurt the system and how do we know how many?

What are other considerations for a self-sufficient water garden or mini pond?  

Where do we start looking for information on this kind of thing?  

Lol.. This is obviously a tricky post. Make them wonder, use critical thinking, research... I like it.

Well.. you didn't mention a pump so. I consider a filter to be something totally different than a pump, even though a filter-system can include one.

1. Mine would look like a puzzle piece(choice) plenty of nooks and pockets and possibilities. Varying in depth from 1 end to the other, shallow to deep. based on my imagination while constructing not based on a plan. Although plans can be beneficial sometimes. It would include a little bog filter with possibility for turning on of the other lobes of my puzzle to an addition bog filter if necessary. Including rocks and various underwater element not to overcrowd but provide(ok, somewhat of a plan.)
2. Research plants based on region, climate, requirements like sunlight, depth, characteristics, nutrition. I would try to find various for shade,cover,food etc. Knowing me, I would get to many and have to thin them based on how well the thrived and spread etc.
3. No fish yet, I'm letting my plants and pond as a whole create it's balance. None will be introduced until it reaches what I feel is a decent environment(perfect). Proper ph, O2 lvls etc. Goodness gracious, I've spent $200 on all these testing supplies and chemicals.Test,test,test morning noon and night, noting fluctuations,, this is taking way longer than I expected,,, weeks have passed, I WANT MY FISHESES... patience.. woosaaahhh..2min later I leave for the fish store.
3fish. I'm very picky, it would take serious consideration on the first fishes. I would research to narrow down species that survive well in such a paradise never to outgrow it and live forever and ever in eternal paradiseness. It would only be a pair(breeding) I would buy them as sexed pair, not getting duped. OMG, I have to order and wait!!!. I would acclimate them gently based on the requirements of the pet store(hoping he's not an ex-apple store employee), I should know...after all this research, if i haven't went this far already, consider me an idiot. I would test...probably daily to ensure the optimal lvls are being maintained although I've added my precious pair. I care..sorry if I'm overly concerned on my Preciouses'. I would probably have a live feed camera on them so I could gaze at will and at moments worry. Heavy Rains came, I think I need to test. A cat was drinking, SCAT CAT. The cat sought revenge, I have cat scat..I need to test. My pretend daughter was eating the non-edible plants and puked in the pond..I definitely need to test and test again.. Due to my precocious testing they have survived and thrived and had BABIES. Oh so many babies!! Way to many babies!! No, I can't, never...I will never ever flush my Preciouses Preciouses. I immediately call all my friends...no one wants any...I buy and offer a small fishbowl included...still, no one wants any. I have 15 fishbowls filled and no one wants any....Plan B...Early Christmas for every friend, co-worker and 1 confused convenient store clerk who mysteriously found them on the counter when he turned around....I can't let this happen again....I immediately go home and sell my Preciouses on Ebay for hardly nothing. I let the pump run just to ensure... pump broke...I spent $500 for a pump, fish and fishbowls. Oh no, another $200 on plants going to die.. So upset, I tell my make believe wife I don't want to talk about the pond ever again..The good news. I got a great Job, unfortunately I have to be away from My Family. I leave immediately, damn that pond.
1 year later..
I am so glad to be finished with that project. I come home, kiss my make believe wife and daughter. Pour a nice drink and walk out on the back patio. THE POND!!!  "HONEY!!!"
It was beautiful, crystal clear with a few Koi and a few edible plants..A new raised border with edible plants and rocks all around. A nice dome net that protected it from leaves and critters off to the side...No sound, no pump!!!
"Honey, how did you do this???"
She said, "Do you remember that man that used to work at the AppleStore? Mr. Ranson?..."He owns the fish store now and pretty knowledgeable about this kind of stuff. He led me to this website called Permies.com and I learned everything I needed to know.", It was easy"
They aren't a pair are they?
She said" No Honey, Mr. Ranson ensured me they weren't"   0.0

I pray everynight those 2 beautiful Female Koi can't ever have Babies together.

I love my make believe wife who takes good care of Our make believe pond.

THE END

I used to have an aquarium. It is a small permaculture. You need balance. Fish produce nitrogen and plants use it. And so on. You have to create good micorbial colonies before even adding fish.

In a garden pond, you will probably get nitrogen from surface water leakage. If one would like to add fish, there would need to be lots of plants to balance them.

My advice is to fill it with natural water, not chlorinated tap water. Plant lots of swamp plants. And let it create its own balance. You need lots of microbes - they will keep the balance. Only Gaia can provide them. If you get cyanobacteria, you have too much nutrients in the water for that amount of plants. So add plants.

I closed on of my swales with a dam this year. It principally became a long pond. It has lots of new plants growing there, is teeming with linsects and smells nice. My chicken prefer to drink from there, although they have resh tap water in a bowl.

I have heard that there are plants that clean and filter water though I don't know which ones other than water lilies.

I ask Mr. Google for help with some other plants:

https://pondinformer.com/plants-that-clean-water/

I hope this list of 12 plants is of interest to you or others.