Ongoing saga of death

[David604]

Hi All,
I purchased a home and moved in July. The home came with 2 Koi ponds(plus 2 turtles). The previous owner said he had Koi for years, with rare issue.

Once I moved in, within a few weeks we lost the 3 fish. I suspect it was due to an issue that caused the auto fill valve to run for 24 hours. I have since turned that valve off.

After a couple of weeks, I had a few more fish added. It was not long, before on died(suspected from using old rain barrel water) and so I had the remaining ones removed to a housing tank.

I then worked with a company to drain the ponds and remove all rocks and gravel(1000 lbs or so) which tripled the depth. I also had a main drain added in the lower pond and a UV light added as well. I also had the "filter" replaced with a superior filter that drains onto the sewage drain and is filled with bio media and plants.

After about a week later we added fish and everything was fine for 2-3 weeks and then over the course of a week they all died. We have been suspicious about sprinkler system which runs for 2 minutes in the area and possible pest chemicals)I then did a potassium permanganate treatment and a couple of weeks later we added tester fish(on Saturday). This morning, over time, they all died. I just did another PP treatment and have ordered clay.

The company I'm working with and I are completely out of ideas and stumped. The water tests all look solid. Really want to make this work, but feeling beat.

 

[Meyer Jordan]

When you say the water test results look solid, what are the actual numerics?
Stop any pond treatments until you determine the cause of the deaths. PP treatments can wreck a biofiltration system if done improperly or too frequently.

 

[David604]

Ph - 7.6
High range PH 8.0
Ammonia - 0
Nitrite - 0
Nitrate - 0

 

[Meyer Jordan]

Did you test for Dissolved Oxygen?

 

[David604]

No, I don't have that test. Should I get one?

 

[Tula]

Does the sprinkler system have back flow protection, some type of check valve?

 

[David604]

There is basically a pretty string current of water flowing from the upper pond to lower and filtering flows into the upper pod and then in the lower pond is another water feature(fountain fed from UV light)

 

[David604]

Does the sprinkler system have back flow protection, some type of check valve?

I'm actually not sure. There are an array of valves in one area. IS there a way to check so I can answer the question. I think the previous owner let the sprinklers run for 4 minutes. I had them completely off for a while but plants started to brown. The house does have a whole house filtration/softener system and an RO system under the kitchen sink, which send small amounts of waste water into the upper pond.

 

[Meyer Jordan]

No, I don't have that test. Should I get one?

Yes. If you are going to test then all major parameters should be tested including not only Oxygen but also Alkalinity (KH) and Hardness (GH).
I would discount your sprinkler system as a culprit

 

[Tula]

Our plumber told us of a situation in a neighboring state, where there weren't check valves on the sprinkler system and there was a large fire in the area and with no check valves, the fire pumps pulled water through the sprinkler system, which contaminated the drinking supply with pesticides from the lawn service. Upon further thought , not sure that would apply to your situation. Is your lawn / garden, treated with pesticides , that could be washed into the pond?

 

[David604]

Okay, is there a particular kit you recommend for that and I'll grab it from Amazon. Thanks

 

[David604]

Our plumber told us of a situation in a neighboring state, where there weren't check valves on the sprinkler system and there was a large fire in the area and with no check valves, the fire pumps pulled water through the sprinkler system, which contaminated the drinking supply with pesticides from the lawn service. Upon further thought , not sure that would apply to your situation. Is your lawn / garden, treated with pesticides , that could be washed into the pond?

We did start having a pest guy come out and spray and provided instruction to stay away from the pond area. It's possible they may have gotten too close once and I have since underscore to not even go to that part of the property to spray. We are now under Winter mode so they only come every other month and I will cancel the service soon. That is one of the reasons it was recommended I do the PP treatment and why I'm getting clay. I'm also trying to find out when the roof was put on. Solar panels went up this year. We do have gutters and doesn't look like roof water would flow into the ponds.

 

[David604]

Yes. If you are going to test then all major parameters should be tested including not only Oxygen but also Alkalinity (KH) and Hardness (GH).
I would discount your sprinkler system as a culprit

I found some reasonably priced tests and they are on the way.

 

[morewater]

I would look at the pesticide/herbicide as the main culprit. All of your water parameters (as reported) look fine. I don't really suspect the roof run-off. Do you have an overflow outlet for the pond?

Heed Meyer on his queries.

 

[David604]

I would look at the pesticide/herbicide as the main culprit. All of your water parameters (as reported) look fine. I don't really suspect the roof run-off. Do you have an overflow outlet for the pond?

Heed Meyer on his queries.

Anything further I can do to test for such chemicals or truly remove them?