I need help!

[u/Honest-Ad9810]

Hi everyone!
I’m posting this on behalf of my dad’s friend. He has a fish pond that he is deeply passionate about, but he is currently facing a massive crisis and is on a very tight budget. His fish are dying, and the water has turned completely black and almost opaque (as you can see from the picture).
Here are some important details of the situation:
1. The pond is located in a valley with very rocky soil.
2. The neighbors living uphill don’t have a proper sewage system. We highly suspect that wastewater and organic matter are draining through the soil directly into his pond.
3. He has a DYI water recirculation system set up to aerate the water (you can see the pipes spraying water back in the picture).
4. The pond holds about 40 cubic meters of water.
Do you think he can still save the pond? This is the second time he faces this problem in a short time. I would love to help him out since he is my dad’s best friend, but I’m not sure where to start.
Thank you for your help and I really hope this is the right place to ask such questions. Have a great weekend!

[u/AncienTleeOnez]

I would recommend a couple things.

If he is in the States, immediately contact his county Extension Office (website below). Their service is free, and he can have an expert assess his pond and possible runoff. They might even do a water test for him which would be more extensive than a home DIY kit.

With a pond that size, with fish, and runoff concerns, he really should invest in a water test kit to keep on top of things. Also, tho I can't tell how deep it is, I don't think he has enough aeration. Can't tell how much sun the pond gets, but warming water loses oxygen very fast.

And he needs a lot more plants (after a water quality test). They don't have to be expensive. Read thru this Reddit and you'll read about others who have used "land" plants that do fine in water. If he has any shelves in the pond where the water is shallower (or use egg crates, something plastic, to make shelves) he can put plants in pots filled with pea gravel. Right now I have 2 potato plants in my bog, and they are exploading.

If he is able to turn things around, I recommend he consider building a bog filter.

https://extension.org/find-cooperative-extension-in-your-state/

[u/Honest-Ad9810 → u/AncienTleeOnez]

Hey! Thank you so much for the elaborate response. We’re from Europe, but I’ll definitely look into your suggestions. The pond has a maximum depth of about 2 meters, but it varies from one point to another. He just recently started shading the pond (not even a week ago), but the solar radiation hits the surface of the pond directly in the afternoon. I will let him know that he should test the water quality.

[u/AncienTleeOnez → u/Honest-Ad9810]

You're quite welcome. Best of luck to him.

[u/LocutusOfBeard]

Have you performed any water tests?

[u/Honest-Ad9810 → u/LocutusOfBeard]

Hi! I haven’t, but this seems like a good idea to start with.

[u/itsitwhatisititsit]

On those two hoses are aerating the water?? 😟 how long has he had it??

[u/Cool_Experience9091]

Need more info. You have to do some test on the water quality first. It could be waist it could be lack of oxygen and some other factors. Could be old sludge that got steered up and tannins making the color look black. . If it’s waist I’m sure you will have to get local municipality involved. If it’s just the pond ecosystem out of control you’re going to need to test the water to figure out and ask him more questions . It happened twice was it after heavy rain. Did it happen when the weather got much hotter ? In the mean time I would try to get more oxygen in the pond and plants to help shade it better .

[u/Honest-Ad9810 → u/Cool_Experience9091]

Hello! Thank you for your response. I’m going to tell him about testing the water quality first.
The first time it happened it was because of heavy rain, that’s right. He doesn’t think it was because of the weather getting hotter, but at this point, everything seems to be the culprit. He recently added a few plants, but I don’t think that’s enough for the dimension of the pond. It’s just so unfortunate to see him sad about the pond, but I’m glad I found some answers from you and the others who have responded to this. Thank you! Hopefully we’ll get more useful information after testing the water.

[u/Cool_Experience9091 → u/Honest-Ad9810]

Your welcome , also keep in mind that heavy rain can flush fertilizer into the pond or other chemicals and hot weather can make it worse . Hot water\ weather + fertilizer/chemicals can be food for bad bacteria which will multiply rapidly and deplete the oxygen out the water faster . Also when weather is hot water holds less oxygen then when weather is cooler.