Pump died...so did my koi

[icerabbit]

Kind of true. Bacteria in filter will die out after about 48 hrs. Best to send the initial outflow to the garden and not the pond. Since the bacteria dies, it can take a few weeks to get the right balance of bacteria to keep the water chemisty right. Waterbug has talked in other posts about new pond syndrome. Basically the same thing here so the fish die of the wastes in the water not neccesarily the filter contents that died off.

Craig

Thanks, Craig. Yes, toxic was my wording just to remember not to do it. He was indeed talking about all the beneficial bacteria dying etc. I understand it would be a combination of lack of circulation & filtration during the time it is shut off (especially if overcrowded) and then possibly flushing some "waste / filter content" into the pond. Fortunately it was a small pond and it hasn't been a problem flushing the filter content out (outdoor canister on quick disconnect, purposely chosen) and doing a partial water change, like with an aquarium.

 

[CometKeith]

Another possible effect of a pump not working might be learned from an article that ran in the newspaper today. They are predicting that larger fish will die off in many of the oceans as water temperatures rise. The Indian Ocean is predicted to lose 25% of it's fish because of this by the year 2050. The article said part of the problem is that as the water temperatures go up the lighter water that is more oxygenated does not mix as well with the deeper water that is cooler and the fish that are deeper become oxygen deprived. I wonder if this same principle would be true in a pond that had a broken pump. I always thought of a pump that moves water around helped oxygenate the top layer, but never thought of it's benefit to mixing until I read this. If your larger fish were deep maybe the top layer of oxygenated water wasn't getting mixed with the deeper water enough for your fish to survive. If this is true then we can also learn something about pump placement and make sure to place a pump low enough in a pond to pull up cool water from the bottom and mix it with the rest. http://articles.chic...h-stocks-oxygen

 

[icerabbit]

Interesting.

I never looked at the oxygen levels and dissolved oxygen details, and I didn't think there would be that much variation between seasons and even have a daily cycle with oxygen swings in a single day whether it is sunny or overcast, etc. Read some interesting things online this morning. Just haven't found yet what the critical level is. May read more on it later.

 

[capewind]

What an awful situation to come home to! Wish the OP would post more info so we could all learn from what went wrong. Many people completely shut down their pumps in the winter, so there has to be more to this then just the pump dying...

 

[Craig58]

Icerabbit:

About 5mg/L is the minimum for carp which is considered a warm water fish. 6 mg/L for coldwater fish like Trout. (reference: http://creekconnecti...xygenSheet.html )

A real interesting thing to watch, (yes.. I'm a bit of a Nerd), are the DO levels in a natural creek nearby . The Federal Government sponsers lots of realtime mointoring stations around the country that you can book mark and watch and track on the web. Each station is different and may only have a few conditons monitored. For others you can see values for Water gauge height, pH, DO, Turbidity, Rainfall, temperature, etc. You can clearly see how the DO changes throughout a given period and you can usually see a marked difference between the daytime and night time levels as the water temperature changes and the aquatic plants switch from making O2 to consuming O2. You can also see correlations with rainfall, waterflow, etc.. It's a great learning tool. Our local stream runs between 8-12 mg/L for DO and can change 3-4mg/l between day and night time readings.

This is a link to a stream near me that I watch regularly. I can also look at it to tell me if my favorite park for running the dogs is flooded out or not after heavy rains and saves me a wasted trip and disappointed dogs. I know if the water gauge on the stream is at certain levels, the park is flooded.
http://waterdata.usg...wis/uv?01481000

The web site is very interactive and you can adjust the charts, look at different time periods, get tables, copy to Excel, all kinds of nerdy stuff.

Craig

 

[icerabbit]

Thanks Craig. Interesting read. I was aware that oxygen levels are lower in the summer, which is a more stressful time for fish, and pond owner to keep everything in check. But, like I said, I had no idea oxygen levels would swing that much between day/night sun/clouds.

But, like Capewind and others have said also, there has to be something more to it. As fish will survive minimal, mild to even severe winters with an iced over pond. Not everybody uses a de-icer or aireator. Certainly not in nature. Many people shut their pumps down for winter. I know ponds that have frozen over several times for a few weeks without issue, ponds without a pump, ever. Yet fish continue to live.

The only times I've seen a fish kill in nature is when there are issues with algae, extreme heat in shallow water or spraying/chemicals. One time a company was hired to do weed / algae control in the canal neighborhood behind our property in Florida, they came with an airboat, sprayed everything ... a few days later all the fish were floating.

I know with my aquarium it is all about water quality.

We'd need to know more about the size & volume of the pond, plant life, fish population, ... were there algae? ... to figure this out and for anybody to be able to give recommendations for the future.

 

[Craig58]

The ability for water to hold DO goes up quite a bit as the water cools. In the winter time the amount of DO the water can hold is so high that there rarely is an issue with lack of O2 for fish even in iced over ponds. Also, since they aren't moving or feeding normally, their need for O2 is way reduced. In winter, death from an iced over pond is usually caused by toxins in the water that can't be exchanged to the air fast enough due to ice conditions. The gases usually come from dirty ponds with lots of decomposing leaf and stick debris. Every case I've heard of heavy winter deaths was either due to lots of junk in the pond or a solid freeze of the pond top to bottom due to lack of depth. In addition, there is little plant activity to affect DO in the winter. So in cold weather DO stays high and doesn't fluctuate much hour by hour or day to day.

Here's a link to a DO vs. Temperature Chart. http://www.google.com/imgres?imgurl...+chart+temperature&hl=en&sa=X&tbm=isch&itbs=1

In winter at around 40F(5C) water temperature the water can hold about 13mg/L but at 95F(35C) it can only hold about 7mg/L. So if Carp (Koi/goldfish) need about 5mg/L you can see how in the summer in high temps, it wouldn't take much of a swing to get down to critical levels.

In the summer, the amount of DO the water can hold is greatly reduced at high temperatures and the fish are now consuming much higher amounts of O2. In the summer the plants/algae play a critical role in DO. During the day plants make O2 and increase the DO in the water. But when the sun goes down, these same plants/algae now consume the O2 in the water. The plants can get by on much lower amoutns of O2 than the fish. When you hear of people having a large die off of fish in the summer and they say "they were fine last night and this morning all my favorite biggest fish are dead" this is usually, (not always), an indication of a DO issue. The biggest fish have the biggest O2 demand and usually will die first. As the bigger ones die, it makes it easier for the smaller ones to make it through the night. Once the sun comes up, the plants stop consuming O2, and they now make O2. The DO goes up and the pond looks fine to the owner. Usually this happens in ponds with high fish loads, and shallower ponds where the general water temperature can swing a lot in a day,

You can see in the DO chart linked in the previous posting above for my local, natural stream where DO can vary as much as 3-4 mg/L between day and night. That's a free flowing, constantly moving, 2-3 foot, usually cool temperature, fairly wide creek with lots of surface area, and many natural, bubbling areas for aeration. Think of how much more of a swing in DO you could get in a small pond, (

 

[icerabbit]

Excellent points and explanation, Craig, and a valuable image regarding oxygen saturation points dropping from 13 @ 40F down to 7 @ 95F in a near linear fashion. Certainly shows the potential for issues with heat waves in cooler regions and the need for continuous vigilance in others. But it hasn't been that warm though in the past two weeks, in the northeast.


I vaguely recall a fish kill at a small koi farm, back when I was a kid and we must have been shopping for fish for the pond or aquarium, but have no idea about what season it was or anything.

Johnnie doesn't have a gallery photo of his pond, but his previous topic shows a few partial photos of his pond. Doesn't look very big and might be on ground, or is at least partially above ground.

 

[CometKeith]

craig58, those are some of the best charts and explanations I have seen on the web about fish ponds and dissolved oxygen. Everything there substantiates a lot of what you hear from various sources, but I like the way it is very formalized and presented in a scientific format. Now can you post a few charts and explanations how to predict the movement of stock prices or housing prices? lol....

 

[Big Lou]

Boy, you guys have truly opened up my eyes to water complexities. Thanks. Years back the beautiful koi pond at Ft. Worth's Botantical Gardens suffered a massive koi loss. I've forgotten the cause but the site of hundreds of dead koi was shocking.

Now, if there were ways to rid America's waterways of harmful invasive carp without killing other fish species would be good.

 

[Craig58]

.....how to predict the movement of stock prices or housing prices? lol....

Yeah.. I've tried that already and didn't have much luck with it! :dunno:

[sub]Craig[/sub]

 

[CometKeith]

Craig, Not even a few predictions about commodity prices based on the weather??? I would think that would be simple compared to what you figured out for dissolved oxygen.

 

[Craig58]

Nope. I had agriculture economics back in college, (BS Animal Science), can't say it was my favorite subject so I think I'll leave the commodities alone for now! The professor must have thought I had promise though cause he kept bugging me to minor in Ag. Ec.

Working on trying to use the mid day returns of the various European and Asian indexes to predict some of the spyder indexes when the US markets open so I can buy or short depending. Some success but I don't have the right combinations yet. Hoping to get a 60-70% success rate eventually. But I don't do it seriously enough right now to make much headway on it.

Craig

 

[CometKeith]

We are getting off the dead fish topic, sorry johnnie..., but i knew you either were or could be one of those types with the kind of analysis you were doing for fish and that your talents could be applied to something more lucrative. My oldest daughter's boyfriend has a math degree and trades S&P futures and does well. He is backed by a group and gets 50% of the winnings but doesn't risk his own money except what he made that year.His trading account money got lost when MF Global went down and his boss put 7 figures back into his account so he could trade again. He does the quick in and out type trades and doesn't keep positions but claims to be an expert on the economy. I would keep it up Craig. I'll bet you hit on something good at some point. Even if you could be right 55% of the time on a consistent basis you can make a lot of money. It works for the casinos all the time!

 

[Johnnie]

Guys, thankyou all for replies. Here are updates.

I pumped out and replaced my 7'x7'x3' pond with 1,100 gallons of fresh water. I replaced the broken pump with another one to keep the "fountain of life" showering down on the surviving koi (See photos below).

"Fountain of Life"
The pump rushes water thru the 4,000-hole-nozzles to oxygenate the water for koi. When the pump died, so did 6 out of 7 koi.

"Amphibian" has survived the broken pump accident. It's 8 years old, 19-inches & 9 LBs.

I purchased and restocked the pond with 5 more baby koi. They've stayed away from "Amphibian" and hidden around the pump. Go figure.



It seems I don't have much of luck with ponding. Do you guys remember this bad incident on the Halloween of 2011?

My pond costed me $2,500 to clean up. The tree guys came to cut down a giant tree near by my pond and clean up the rest of debris. What else will come against me to make me quit ponding?