I'm so upset! Two dead Koi! l

[MitchM]

Checked my levels and everything appears good except the ammonia level is a little high at .50 ppm. Ph is 7.4, Nitrate and Nitrite levels are at 0.

Do you happen to have a reading on the KH and GH values?
PH swings can cause the fish significant stress.
Is algae the only plant present in the pond, other than lilies?

The pond design seems to have a large shallow area and a small deep area. How large is the deep area?
Is it possible the koi could have become trapped in the shallow area during ice over?
What size are the fish?

If you don't have an O2 reading we'll have to leave the pond breather discussion for now. We can neither prove nor disprove if the fish died because of low oxygen. If the breather was working properly the whole time, it would have provided plenty of aeration, as long as the fish were not too cramped into a small space in the deeper portion of the pond. I'm assuming the breather was situated close to the waterfall.

I'm not clear as to how old the pond is. You say you inherited it but it looks like a newly set up pond.

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mitch I always enjoy a good debate and please don't take it personnel. I respect you for defending a product you believe in.

I don't mind the discussion, but your comments about the low wattage tells me you don't understand the operation of the unit so we'll have to agree to disagree.

.

 

[qclabrat]

Sorry for your losses Angela,
I'm not sure if it was asked but when did you stop your pump for the season and when did you add the pond breather?

 

[Lisak1]

Is it possible the koi could have become trapped in the shallow area during ice over?

That's interesting that you mention that. We had a fish last year that I swear just got caught in the ice and froze to death. I noticed a few days earlier that he and a few of the goldfish were up, rooting around in the shelves when all the other fish were staying near the bottom. The temperature dropped pretty rapidly and when I looked out at the pond a day or two later I thought "that fish is still swimming near the top - weird!" When I went out to check I realized he was actually frozen in the ice. He wasn't belly up - he looked just like he was swimming, except frozen. I figured he was just too dumb to get to the bottom when the water started to freeze around him!

 

[AngelaM]

Sorry for your losses Angela,
I'm not sure if it was asked but when did you stop your pump for the season and when did you add the pond breather?

I stopped the pump around the end of October. The pond breather was in and running a good 3 weeks before we had any ice.

 

[AngelaM]

Do you happen to have a reading on the KH and GH values?
PH swings can cause the fish significant stress.
Is algae the only plant present in the pond, other than lilies?

The pond design seems to have a large shallow area and a small deep area. How large is the deep area?
Is it possible the koi could have become trapped in the shallow area during ice over?
What size are the fish?

If you don't have an O2 reading we'll have to leave the pond breather discussion for now. We can neither prove nor disprove if the fish died because of low oxygen. If the breather was working properly the whole time, it would have provided plenty of aeration, as long as the fish were not too cramped into a small space in the deeper portion of the pond. I'm assuming the breather was situated close to the waterfall.

I'm not clear as to how old the pond is. You say you inherited it but it looks like a newly set up pond.


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Yes Mitch it's a new pond. I bought it used last summer so it hasn't been in a year yet. I didn't get much choice when it came to size of setup since the liner was already cut. I had the pond dug basically the same way she had it before other than I added the shelf. I actually made the pond a half foot deeper than the way she had it. I have good algae growth, water lillies and that's it for plants. I just have a small pond test kit. What do I need to test GH & KH values? The pond starts at 4' deep at the half way point of the pond. Yes I had the breather between the waterfall and the half way point so it was definitely in the deep end. When I found the two dead fish, they had surfaced on the deep end of the pond against the edge where the ice had thawed. The shallow end was still froze so I don't think they got trapped there. These fish generally hang in the deep end all the time unless I throw food in the shallow end. The Koi are about 12-13" long.

 

[AngelaM]

Sorry to keep dragging this on folks! I am still so new to this. I just don't want to lose any more fish. I am a huge animal lover and this just kills me. I don't want to get any more fish until I get down to the bottom of this.

 

[Lisak1]

Don't be sorry @AngelaM ! It's good to talk it out not only for your benefit but for anyone who might have a similar issue in the future. We all do this because we love our ponds and our fish - losing them is so sad! Trying to figure it out is important for you and for the rest of your fish.

So the pond was already in existence but you rebuilt it from existing liner, skimmer, filter, etc - did I get that part right?

 

[MitchM]

You're not dragging this out at all.
This is all normal information that we need to know about our ponds.

A KH and GH test kit is available from API:
https://www.apifishcare.com/product.php?id=587#.WpdTJGYZNhE
Knowing those numbers will help you make sure you have enough carbonates and minerals so you have a stable PH. That is especially important going into winter because you won't be able to make any adjustments to your water once you have ice cover. A pond without any type of plant filter such as yours is more susceptible to rapid changes in water quality.

You mentioned that a lot of leaves fell into the pond before ice over. What was the plant/tree species that the leaves came from?

Did you notice anything unusual about the dead koi's appearance as you removed them from the pond? Mouth open, red/inflamed gills, discolouration, sores or fungus? Depending on when they died, their bodies could have deteriorated somewhat, but any observations could help point to a cause.

 

[qclabrat]

I stopped the pump around the end of October. The pond breather was in and running a good 3 weeks before we had any ice.

so there was no aeration for several weeks? I had may largest GF die late last fall between the time when I shutoff the pumps and added a new aerator. It was only about a month but I suspect it was long enough to impact the larger fish. I ran all the normal water test and all seemed fine, I even did a close up inspection of the fish and all seemed perfectly normal. Funny thing is that I thought fish swim to the surface when oxygen is low, but perhaps since water temps were in the 40s, it stayed on the bottom despite the need for oxygen.

 

[AngelaM]

Don't be sorry @AngelaM ! It's good to talk it out not only for your benefit but for anyone who might have a similar issue in the future. We all do this because we love our ponds and our fish - losing them is so sad! Trying to figure it out is important for you and for the rest of your fish.

So the pond was already in existence but you rebuilt it from existing liner, skimmer, filter, etc - did I get that part right?

Yes that's correct Lisa. She had the pump, filters, waterfall, basically everything except an aerator. Even though she only used an aerator for winter months. (That's ALL she used!) It died on her last winter so that's why she no longer had it. Really wishing I would've got one now. I feel like such a failure! This woman literally did bare minimal and never had ANY deaths! Ugh!

 

[AngelaM]

You're not dragging this out at all.
This is all normal information that we need to know about our ponds.

A KH and GH test kit is available from API:
https://www.apifishcare.com/product.php?id=587#.WpdTJGYZNhE
Knowing those numbers will help you make sure you have enough carbonates and minerals so you have a stable PH. That is especially important going into winter because you won't be able to make any adjustments to your water once you have ice cover. A pond without any type of plant filter such as yours is more susceptible to rapid changes in water quality.

You mentioned that a lot of leaves fell into the pond before ice over. What was the plant/tree species that the leaves came from?

Did you notice anything unusual about the dead koi's appearance as you removed them from the pond? Mouth open, red/inflamed gills, discolouration, sores or fungus? Depending on when they died, their bodies could have deteriorated somewhat, but any observations could help point to a cause.

I didn't notice any injuries aside from a little bloating and decay. The fish looked fine. No redness, find looked goodni redness or sores. I do believe one had its mouth open. I don't recall if the other one did. I think it did also. I'm not sure what type of tree, probably a few different ones as we always have a breeze through here. Mostly oak, maple, and ash trees. My Ph level did lower since fall. It was very stable at 8.5 all summer and fall. Now it's 7.4. I do have a mesh bag of oyster shells in my pond that someone recommended to avoid Ph spikes.

 

[AngelaM]

so there was no aeration for several weeks? I had may largest GF die late last fall between the time when I shutoff the pumps and added a new aerator. It was only about a month but I suspect it was long enough to impact the larger fish. I ran all the normal water test and all seemed fine, I even did a close up inspection of the fish and all seemed perfectly normal. Funny thing is that I thought fish swim to the surface when oxygen is low, but perhaps since water temps were in the 40s, it stayed on the bottom despite the need for oxygen.

The lady who previously owned this pond never used any aerator except for winter months. Then that was ALL she used for winter. No heater, nothing else. So now that I am definitely getting an aerator, any recommendations on a good one? How large should I have for this size pond?

 

[AngelaM]

Mitch, I see you have experience with the rubber membrane diffusers. Do you use the Easy Pro brand? Do they just attach to any aerator? Thanks!

 

[audioenvy]

Fish are extremely unlikely to die due to high total ammonia (TAN) in winter. This is because most of the total ammonia is in harmless NH4 (ammonium) form rather than the harmful NH3 (free ammonia) form when the water is cold.

It's possible that there was a pH swing--but this also seems unlikely in winter due to the limited depletion of KH in cold water (but you should test it to be sure).

The amount of total dissolved oxygen in cold water is much higher than in warm water--but if there is nothing to introduce new oxygen into the water as existing oxygen is depleted then you can definitely reach a low oxygen situation where (normally) the larger fish would be the first to die.

Parasites/bacteria are also a possibility but are much less active in very cold water.

This leaves the cold water itself and yes some koi cannot seem to take super cold water as well as others.

I put a winter cover on my pond for the first time this year and I'd recommend it to anyone and everyone. Even if you can only cover a section of the pond it's better than nothing.

 

[MitchM]

Mitch, I see you have experience with the rubber membrane diffusers. Do you use the Easy Pro brand? Do they just attach to any aerator? Thanks!

The diffusers have a barbed fitting that fit any hose. I recommend using weighted hose.
My aerator selection here is limited compared to what is available in the USA. I don't recall the brand.
I understand that disc type diffusers are more durable.

What do you have for biofiltration (filtration) for your pond?

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