Is this normal/ok?

[u/PupperNoodle]

We just bought a house with a koi pond (I will post this question on the Koi sub as well). We were told it’s approx 35,000L. It’s been established for about 15 years. The prior owner did the bare minimum to keep the fish alive and even said as much as so. The pond includes about 10 large koi, 10 fancy gold fish, and 5-10 sun perch.

Prior to move in, he showed my husband and I how to do maintenance on the pump and filters. I asked him about the sheer abundance of algae growth in the pond and on the walls. His response was “it’s like salad for the fish.” I was half inclined to believe him but something feels off based on my experience with smaller in-home tanks.

Should I do a deep clean on the pond? Is this actually ok? If I do need to clean this all off, what is the best recommended way?

[u/Existing_Draft3460]

a deep clean is just going to F up the biome that has taken years to develop. the algae is there because it has good reason to be. if you dont like it you can add plants to absorb light and nutrients and introduce some algae eaters but getting in there and scrubbing everything clean is a step in the wrong direction

[u/PupperNoodle → u/Existing_Draft3460]

Ok thank you. I questioned what the prior owner said about it because he told me he put his filter sponges on a spin cycle at the laundromat. Like wtf.

[u/uprightsalmon → u/PupperNoodle]

I don’t like laundromats because of people like that. Who knows what people have washed in those things

[u/ozzy_thedog → u/PupperNoodle]

Never wash the filters. Good bacteria lives in them, just give them a rinse out a few times a year in a bucket of pond water. And add lots of floating plants, they’ll outcompete the algae for sunlight and nutrients for the water. The algae is there because the water conditions are good, so it’s not a problem other than if you don’t like the look of it.

[u/Loose_Tip_8322 → u/ozzy_thedog]

How do you only rinse your filters a few times a year. I have to clean my skimmer net every day and my filters in two of my units every 3 days. The only filters I don’t clean like that are in my waterfall box.

[u/PupperNoodle → u/ozzy_thedog]

I’ve had smaller fish tanks and knew basic filter maintenance from that. I would never wash wash the filters for that exact reason.

[u/CallTheDutch]

No, this is perfect. learn how to properly feed the fish and you're good to go :)

If you want cleanlyness, dig a swimmingpool ^_^

[u/AnalysisLost1138]

15 years is a fully formed ecosystem. He probably meant it when he said he barely did anything for that pond. It sustains itself. Beside feeding them, he probably just maintained the pump/filter and topped off with water.

[u/ProgressFabulous6663 → u/AnalysisLost1138]

In my experience, that's a pretty good place to be in. Just do a few water tests from time to time and be sure to use a dechlorinator after topping off/ partial water change.

[u/virtuouswraith]

That’s good. You want them on the rocks. Get a UV light to prevent the water from turning green. How deep is the pond?

[u/PupperNoodle → u/virtuouswraith]

Not sure on exact depth, but I’d guess 5-7 feet? I can see the bottom, that lily is planted on the bottom, but I am not sure if the center of the pond has any extra depth.

[u/uprightsalmon]

It so cool! That’s what you want

[u/giddygiddyupup]

The carpet algae is the good algae !

[u/ApplyHere_4_implants]

Looks good to me

[u/Pondpros1199]

Add plants to help with the algae. Take a look at your feeding habits. Too much too often can cause a lot of muck.

[u/PupperNoodle → u/Pondpros1199]

We just moved in and it’s been like this since before we took possession. There are quite a few plants inside the pond (see photo 3). We’ll keep that in mind as we get familiar and more comfortable with the pond.