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Related Articles: Environmental Pond Disease, Koi/Pond Fish Disease, Gas Bubble Disease/Emphysematosis, Pond Parasite Control with DTHPHole in the Side Disease/Furunculosis Goldfish Disease,

Related FAQs: Pond Environmental Disease 1, Pond Environmental Disease 2, Pond Environmental Disease 3, & FAQs on Pond Environmental Disease: Prevention, Diagnosis, Causes: Cumulative Stress, Predation, Poisoning (Algicides, Metals, Pesticides...), Metabolite Accumulation, Physical Trauma/Damage, Electrical, Troubleshooting/Fixing, & Pond Fish DiseasePondfish Disease 2, Pondfish Disease 3, Goldfish Disease,

Different species have a much greater/lesser tolerance for DO (Dissolved Oxygen) and CO2 and other gasses... And size counts... Usually smaller individuals have more percentage gill surface area...

Aquatic Gardens

Ponds, Streams, Waterfalls & Fountains:
Volume 1. Design & Construction
Volume 2. Maintenance, Stocking, Examples

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by Robert (Bob) Fenner

Help! My Shubunkin is not acting right.      9/21/14
My pH is around 8. I have a 625 GPH submersible filter with a uv sterilizer and a fountain attachment. I just cleaned my 765 gallon pond. I started yesterday afternoon and finished this morning. I had to put my Shubunkin in a 50 gallon container with 11 other comet goldfish overnight. I about lost one of my comets. But that fish recovered and is doing fine. Now this one is acting strange. It is gasping at the surface of the water and darting around. The other fish are hiding in their fish shelters during the heat of the day. This is normal. Usually my Shubunkin hides with them. Not so today.
I used a new type of pond bacterial additive too.
<Why? What additive? To fix what problem with the pond?>
It keeps coming up to me as if asking for help. Is my fish stressed because of the water change?
<Fish can react to sudden changes in pH and temperature by swimming oddly, but typically most/all the fish will react, particularly within a single species (in this case, Carassius auratus). So if just one Goldfish is acting odd, then there may be something else going on. Examine the fish carefully for signs of physical damage (cats, leeches) or external parasites (anchor worms are not uncommon). Your photos don't really show me anything of significance, but capturing the fish with a net, removing to a white container, and then examining it yourself could be the next step for you.>
Does it have gill damage? Is it just hungry? No red areas or streets that I can see. Some photos are provided below.
Thank you.
<Most welcome, Neale.>

Help#2!      9/21/14
In my last letter to you, do you recall me telling you about the comet goldfish I about lost? Well, turns out now that one is suffering from the same ailment as the Shubunkin. I am almost certain now these two suffered some sort of gill damage from their overnight stay in the 50 gallon tank with the other fish. What should I do with them? Do I humanely kill them?
Or should I just wait and see? Thank you.
<The latter. Damage to the gill filaments -- if not fatal or so severe the underlying bones are damaged -- usually will recover in time. Upping the aeration and/or use of water features to ensure oxygen levels are good will be helpful for this fish of "diminished capacity" at the moment. In fact you may prefer to hold them in a cycled hospital tank where you can keep them out of direct sunshine and excessive warmth (warm water contains less oxygen) so that they heal more comfortably. Should be back to normal within
a month. Cheers, Neale.>
Help #3
The fish I wrote about in my 2nd email to you has died. Found her floating in the pond. Checked her gills before disposing of the body. They were a dark blood red. Is this a sign of gill damage?
<Nope. It's a sign of a dead fish. Haemoglobin, once blood flow and gill (or lung) ventilation stops, turns dark red.>
A photo of the dead fish is below. The 2nd fish was having the same symptoms as this poor fish. Will it die too?
<I hope not. Do see previous emails.>
Thank you.
<Most welcome, Neale.>

re: Help #3      9/21/14
Thank you so much for all your help Neal. All my remaining fish are hiding this morning. Do you think it is due to stress from the pond cleaning? The Shubunkin is still alive as well. Thank you.
<Most welcome and good luck. Neale.>
Help! #4 Update
I got an update for you on my sick Shubunkin. Found my poor Shubunkin dead today. It was up in one of the folds of EPDM liner I have in my pond.
<Oh dear!>
Looked like it had been there a day or two. The other fish seem healthy and active. I have 8 to 7 goldfish now. Hard lesson learned though. No overnight housing in a 50 gallon tank without aeration and filtration. Poor fish! :(
<Indeed. Good luck with the remaining fish/pond. Cheers, Neale.>

Koi problems...trouble breathing  03/25/07 We lost one 10 inch Koi last week. For approx: 2 weeks it was breathing heavy, before it died. Now the others are showing the same symptom, and they are 2 ft+. I am Building A pond outside. These have never been outdoors. They are in A 300 gal Rubbermaid tub. I change water regularly once A week 40%. I heat to 87 Fahrenheit and store the water I use to change with. I don't want to lose these fish, they have been with us for a long time. Can you suggest something to help? <What equipment are you using to aerate the water. You are running this set-up quite warm...a little too warm in fact.  The higher the temperature of the water, the lower the dissolved oxygen in the water is...tis the reason why you take a cold water/temperate animal like a leopard shark and put it in a tropical tank it does not live very long. (Marine example I know, but the concept is the same). You will either have to use serious aeration equipment or lower the temperature significantly, refer to WWM re: Koi fish for specifics.  And are you testing the water chemistry?> Please. Thank you. Sincerely; Fred Elliott <Adam Jackson.> dead Koi 06/26/08 <... Please... fix your English if writing us> the weirdest thing happened , this morning I came out to check out my Koi pond, they were all dead including a goby and a goldfish I have, yet none of the suckerfish are dead. they had no lesions ,cuts, nothing I checked the ph nitrite and nitrate they were perfect. the Koi themselves were sort of inflated and mushy inside it looked like there innards were gushy and one of females um hole? was open and red and it looked cut. one of the males looked like it had a long round balloon coming out of his belly. yesterday they seemed fine nothing really bad to mention. the water seemed clouding and white , and it looked like oil had been spilled in the water and looked like white little pieces of junk was in the pond. can you help me out??? ? ????????????????????? it's so weird, and it was so sudden please help me!! <... Something happened... tis the season... likely either an oxygen depression during the night, and/or a die-off of microbes/algae... need to read and heed re dynamic equilibrium in pond maint., redundancy in filtration, circulation, volume... where? On WWM. Bob Fenner>

Sudden Pond Fish Deaths I have had an outdoor fish pond (150 gallons) for the last 4 years. I only have comet goldfish in my pond. I came home to find the 3 largest fish dead. <<Marina here, I'm sorry to read this.>> I have had them for the last 3-4 years. One of the larger fish was still alive but floating on his side and gulping for his breath. <<In need of oxygen, possibly too much carbon dioxide or worse in the water.>> I tried to save him, but was unsuccessful. I have 4 smaller comets that were their offspring (2 yrs old) that are still alive and they do not have any signs of sickness. I am puzzled as to why the larger fish have died. I have never had any of the Comet fish to die. Our pump messed up and pumped about 70% of the water out the night before they died and we had to fill the pond up that morning.  <<Oh man, there you have it my friend. This is how I lost a whole pond full of fishes once. >> We were afraid that it would mess up while we were at work, so I did turn the pump off.  <<Bad juju - you simply ensured that it would end up the same whether or not the pump "messed up".>> The fish were fine before I left and seemed to enjoy the water change. <<I'm sure they did, especially if it's been a long time since you've done any maintenance on the pond. A build up of mulm/detritus on the bottom would be another reason for sudden deaths - anaerobic conditions may very well have been created with such a buildup, the gasses then build to the point where they are released into the water et voila'! Dead, gasping fishes.>> The outside temperature was around 73 degrees the day they died. I don't know if they died from lack of aeration, but I have left it off before without any problems.  <<It wasn't that, it was such a large change without following aeration. For one thing, the water out of the tap has a great deal of gasses in solution. When you take that water out of the pipe, the pressure that kept the gasses in solution is gone, thusly, the gasses turn to bubbles, hopefully BEFORE the fish breathe them in. If not, they got the "bends" in a manner of speaking. NEVER refill a pond this way with fish and NOT ensure aeration and/or turbulent water movement to ensure this doesn't happen. Let's not forget that if on municipal water chloramine is likely present, bond between chlorine/ammonia MUST be broken chemically.>> I have also done water changes greater than 70 % without any problems.  <<Did you leave the pump off after doing such a large water change? In a situation such as this we cannot ascribe the deaths to any ONE cause, but more likely a chain of events, several root causes coming together for a lethal combination. Do some maintenance on the pond if it hasn't been done already, check the pump and replace if necessary. I LOVE Eponds.com by the way. Fantastic service, incredibly fast shipping, incredible deals on product.>> Any ideas as to what happened to my large fish (10 -13 inches long)? <<Whoa.. they got THAT big in just 3-4 years?? As above, a combination of factors is my best guess here. If you have plants then they help prevent these sorts of problems. If you don't, consider adding live plants. Marina>> 

Koi dead suddenly Dear there, <And there> I have kept a 100 Gallon pond with 5 Koi for about nine months, the Koi is now about 7 to 9 inches, <One hundred gallons? This is way too small a volume for this number of Koi of this size> they have done well. the pond have filter and UV light system, half water change every two weeks. <Sounds like a nice set-up, maintenance schedule> But yesterday morning, they stop eating abnormally, and one dead afternoon. I was so surprised, tested water and changed about 2/3 water immediately. the water rate before water change is as, PH 8.1, Ammonia 0.25, <pH is a bit high... is your tap water this alkaline? And the ammonia is hopefully just left over from the dead fish, and not something you have all the time> Nitride 0, temperature 74. Looked at the dead Koi, no any sign of disease, only have sticky skin, the left four looked have heavy breath, however they looked better after water change. <Good move> The nightmare is not finished, I found another dead Koi this morning, two of the three left fish have heavy breath again, I put this two weak Koi into an isolated basin with salted water and some medicine. Can you image what's the problem I met according to my state, what can I do now to survive the lest life. Thank you very much. Bo <Very likely what you are experiencing is more of a "seasonal" set of circumstances... the water warming up is increasing your fish's metabolisms and reciprocally is responsible for less solubility of oxygen... With such a small volume your fishes aren't getting enough oxygen... this is at least a major contributing factor to their distress, dying... I doubt if they have a pathogenic (bacterial, parasitic) problem... you can add some aeration, keep changing water frequently, but you really need a larger pond if you intend to keep Koi. Bob Fenner>

Goldfish behaviour 7/4/05 Hi <Hello there> I have a very large garden pond - twenty foot by forty plus foot, four feet plus deep at one side, lots of goldish which do breed and so on.  However they do this every year and I now feel I need to know why. They are mostly just hanging suspended in the water, like they were asleep, although they did consent to eat a little yesterday and in the post dawn period they make little bubbles on the surface which linger most of the day. <Ah, yes> Can anyone tell me what they are doing and why?  No filter or oxygenator alas but I have lived here for more than ten years now and have managed so far okay. Thanks very much Angie Watts <They are experiencing changes in the pond due to the season... in essence being poisoned... changes in pH, mixing of bottom water... You might consider adding aeration, biological filtration... that will make this system overall more homeostatic throughout the year. Bob Fenner>
Re: Pond Goldfish behaviour 7/5/05
Thanks very much for your reply.  I found the credit note from the water company when we had to have the concrete pond relined with a butyl liner as it had cracked (September 2003) and I found I reclaimed for 35metres3 not put back into the sewage system. <A good note... in the States we also can at times realize such a saving from notifying our water/sewage service provider> Add to that the contents of 2 x 45 gallon containers, one large fish tank and a paddling pool (for the marginals) I think that works out a pond approx 7,800 gallons, am I about right?   <Mmm, 35 cubic meters of water is about 9,409 gallons...> About a hundred goldfish (although most of them have bred black).  I have ordered a solar powered oxygenator to help things & use barley straw in old tights (last added about three weeks ago) but I guess 2 and half inches of rain the other day really upset my systems. Although I have to confess I was in there the week before taking out some weed!  At the moment I am just spraying the water a little each day to add oxygen. <All good techniques> The fish seem to be okay but after looking through your web site I am resolved to feed them less often than the several times a day they have got into the habit of begging for. It's a great site - I have learnt so much from looking at it. Cheers Angie Watts <Thank you for your kind words, caring and sharing your experiences. Bob Fenner>


Koi unusual habits 8/12/05 Dear Bob Fenner, <Derek, Jenny> We live in the South of England UK and have a garden pond of approx 1,000 gallons and 4 feet deep.  We have 7 Koi (4 being about 15" long).  We also have 16 other fish being a mixture of goldfish and Shubunkins and babies we have reared. <A bit crowded...> We have a very good filter system and water pump in the pond and part change the water and clean the filter regularly.  The water is clear and the fish are all healthy and we have not lost any for 4 years. However,  there is a water outlet pipe which runs from the filter and then the water cascades into the pond quite strongly.  My husband and I are worried because we have recently noticed the 3 large yellow Ogon Koi have taken to sitting under the pipe and letting the water hit them on their head (in fact they almost have their head out of the water to do this and stay there in this position for some considerable time.  It may sound odd, but they are also opening their mouths as if they are trying to drink the water! <Telling>   At first we thought it was only one Koi doing this, but have found the other 2  Ogons doing the same thing yesterday and today.  They seem to do it after about 19.00 hours.  Also all the other fish are around them at the time very closely compacted and almost nudging each other gently.  There is no animosity or bullying.  In the 5 years we have had our fish we have never noticed this behaviour before and we spend a lot of time caring for them and watching their habits.  We are now worried.  Is this natural behaviour?   <Is... for an oxygen lacking environment... you have provided the significant clues... the small size, surface area of your pond, the fact that the Ohgons ("sun-colored fish") are affected most, and the time frame of the commencement of this behavior... What is happening very likely is that with the sun going down, cessation of photosynthesis, there is a rapid loss of dissolved oxygen concentration... by virtue of their breed (all Koi, like domestic dogs, are of the same species), the Ohgons suffer most... and therefore...> This is not a joke email by the way!.  Many thanks for your help in advance.   We have found your website most helpful. Jenny and Derek <The best thing to do... either reduce the bioload here, increase the pond size... and/or add mechanical aeration (bubblers). Bob Fenner>

Re: Koi unusual habits 8/15/05   Dear Crew <Derek>   Many thanks for your speedy reply received the following morning after your email.   I immediately tested the water in the pond and it was reading dangerous on nearly all tests. <Yikes! Glad you were quick to action>   I guess you probably saved the lives of all our fish, as I immediately went to the Water Gardens Fish Farm nearby and bought the bubble making machine for oxygen, pond salt, BioStart, Water Cress and updated our water testing kit. <Great!>   My husband immediately started a series of partial water changes over the last few days and cleaned out the filter again. <Very good>   It didn't enter our minds that the oxygen level was low as the pond and fish have been healthy for 4 or more years. <Happens... very commonly>   Many thanks once again.  We now have happy fish swimming around normally. Your Website is an inspiration!   Regards  Derek & Jenny, England UK <Ahh, my twin wishes... that WWM serve as a source of information... and inspiration! Cheers, Bob Fenner>

Aquatic Gardens

Ponds, Streams, Waterfalls & Fountains:
Volume 1. Design & Construction
Volume 2. Maintenance, Stocking, Examples

V. 1 Print and eBook on Amazon
V. 2 Print and eBook on Amazon

by Robert (Bob) Fenner
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