I have had ponds for years and never had this to happen!
Around Easter I losed six fish over night....I thought it was because the temperture dropped so fast over night..It left me with 4 fish....Once it got warmer again about a week later I changed water and treated as I always do...Lost two more.....Then about two weeks later my pond was smelling bad so I drained it down a good bit and cleaned it....two days later my other two died..Also the tadpoles all died...
Since everything died I drain pond completely but left the plants in and filled it up and treated it....It has been two weeks and have heard frogs in it again...so I got some fish to try again ...Within 20 minutes in water they where dead...They were swimming one second and then dead...almost like they where zapped and knocked dead...they never acted sick or slow....
What could this be and what do i need to do to get my pond back...
Could there be chemicals from the neighbors dog jumping in...or something from the mulch we put out??? We have had mulch there and never brothered them before...
I am taking everyhting out and throwing it away...and moveing the mulch away and cleaning it good... What shold I clean it with...Someone said deluted bleach???
Please help me....I love my pond....and don't want to have to fill it in...

Diannemc, Sounds terrible; hope you figure it out soon.

For whatever it's worth, I've had dogs swim in my pond many times; both strays and known dogs. Luckily enough none have brought in anything that has killed my fish. I live in a subdivision with nothing but sod; I worry about fertilizer they may pick up with their feet. I know that's bad. I don't know about flea collars or flea/tick treatments.

I'd be careful with bleach!!!! I understand it's deadly to fish. I wouldn't even take a chance with residuals (left behind after a rinse). Various house washes I've used have bleach in them so I have to be real careful around the pond.

You might also take a sample of your water down to the pet store, or vet and have it tested.

Good luck. Let us know if you figure it out.

I'm sorry about your fish. It sounds like something is toxic in the water. Are there frogs in the water? Are they okay or are they dying? Frogs are more sensitive than the fish so if they're alive, then it's probably a problem that only bothers fish such as low oxygen, high toxic gases, high ammonia, etc. Yet, to kill in just 20 minutes normally is something very toxic such as chlorine, pesticides, acid (low pH), and so on. Is mulch getting into your pond? Is this a new mulch that you haven't had before? I put mulch around my pond and haven't had a problem. Maybe the mulch is acidic. Test the pH of the pond water which should be 7 to 8. If it's below 6, then the acid would kill the fish. Some mulches may leach acidic compounds. Bleaching it wouldn't get rid of the acid. It's not practical to bleach wood. The wood absorbs the bleach as well so it's never truly fish-safe. Did you add dechlorinator to the new water when you did a 100% water change? Also, since you said the fish looked zapped, be sure there is no electricity in the water from bad equipment. If you can have your pond water tested, do as many of these tests as possible: pH, hardness, alkalinity, ammonia, nitrite, nitrate, chlorine, oxygen, and pesticide screen. I hope you can figure out the problem.

yes, please let us know if you've found the answer. A newbie on one of the Yahoo sites in New York just went thru the same thing. They lost 10 koi at the first shot, and is still looking for answers. I noticed today we haven't gotten an email about how it was going, it's been a few days for her. If she gets back to the site I'll be posting her findings here.

Well I am not sure what it was put I have drained the pond completely out and washed it with clean water nothing in it..just water....drained and washed again..
I throw everthing out plants rocks everything!!! What a job...I remove all the mulch around the rocks on the outside of pond and then washed the rocks...I am going to let it dry for a few days then wash again..let dry then fill..Starting over you might say....I am also getting a new pump... Just in case....Fixin to order some new plants...Going to by some cheap fish to "Test The Waters" Bless their hearts, I hate to do that...but don't know how else to do it..Got to come up with some way to keep my neighbor's dog out....I think that is what did it...she had some kinda stuff on her...That's all I can come up with...We don't put anything around the pond that would hurt it...My husband put out some ammonia but he does that all the time and it has gotten in it put never hurt anything..
I am just sick those fish were my babies.. they would come up and play with your fingers....Thanks for your help...

Diannemc, don't forget the pond starter/dechlorinator!

And, watch your husband! :blink: He's running around with ammonia! :o

Ask him if he likes the pond? :unsure:

What did he put out ammonia for? Did some get in the pond? If so, that certainly could have killed the fish. I can't imagine that a dog in the water would harm the pond fish indirectly unless the dog had some strong pesticides on it like a recent flea/tick dip. I hope things go better once you have it set up again. As Johnny said, be sure to add some dechlorinator.

he put the ammonia on grass..Helps to make it green...It could have gotten in there...But would they have died so fast...?Like I said he has put it out lots of times in the past and never bothered it and i know it has gotten it it before...Maybe too much got in it this time...
I won't let him put it out around the pond anymore just in case...Thanks
As far as the dog they keep her inside and I know they clean her often...and treat her...
I am starting off with a clean slate...The pond is empty and clean going to put fresh water in it tomorrow...Any sugestions besides the pond starter and other?

I would lean more towards the ammonia spike. There's alot ot 'tea' mixtures you can put on your lawn but I've never heard of straight ammonia.

Diannemc, back to your original question; it's looking more like chemical/fertilizer being the cause of your deaths.

Considering your husband is using ammonia, a level of lawn care most of us dont' get to; there's no telling what else (fertilizers) he uses in conjunction in order to green the lawn.

I use a lawn service for my yard. They've explained many times the extreme caution they have to use to spread lawn chemicals around the pond/stream because lawn chemicals are so deadly to fish. A few granules is all it takes. They go as far as to leave signs in the yard telling me when they've been there. That tells me I need to water in the treatment ASAP; thus diluting the chemicals to avoid ducks, dogs, etc. from bringing them into the pond on their feet.

Of course they tell me this, not because they like my fish (although they do), but more to avoid complaints by making me aware the lawn around the pond might not look as good as the rest because of the caution they have to take.

Also be careful with applying sprays, especially on windy days; airborne particles/spray can also blow into the pond.

I suggest adding the following to the fresh water: dechlorinator/water conditioner, good bacteria/pond starter, and pond salt (at <0.05%). Aerate the water well. Check the pH, hardness, and ammonia levels to see how they are. It's too bad you couldn't have gotten a test kit and tested the old water before cleaning it out to see if indeed the ammonia was toxicly high. It is a good thing in a way if it was the ammonia, not good for the dead fish obviously but good that you know what it is so it won't happen again. If it's still a mystery, new fish might die as well. I hope everything goes well!

The other person ( from the Yahoo site ) that had a massive fish death recently just finished a big cleanout. They got conflicting information from their 2 help sources but it looks like it was the algaecide they used. They changed half the water and carbon filters and looks like they haven't lost anymore fish. That's the update from New York.

Still having problems..
Cleaned pond filled with fresh water..Put stuff to clean the water and put pond started in it...even new pump...Waited and them got fish...One died them another..My new pump quit working...it was three days before I got another....Put it in last night..The other fish where fine then at lunch today they other three were dead...Before I took them out of water they were covered with white stuff...obut out of water you can't see it...Ick Maybe???
Now where do I start???

I'm sorry there are still problems. What are your water test results now as far as pH, ammonia, etc.? Ick looks like the fish is sprinkled with tiny grains of salt. It can be seen in or out of the water. Fungus can look fuzzy or like patches of white. When there is a major problem such as poisoning (via pH, ammonia, chlorine, pesticides, etc.), fish may slough off their slime coat. Basically, their outer layer of flesh comes off. That may appear as if they are "covered with white stuff" when in fact its their own flesh coming off. That might appear to lessen when removed from the water. If that's the case, there's something majorly wrong which makes sense since so many fish have died. How many fish died? How many did you add? Did they seem healthy when you got them? How big was the pond (I don't think you mentioned it?)?

I would start with testing the water again for pH, hardness, ammonia, nitrite, and if you can even nitrate, oxygen, and chlorine to rule out those problems. Also, test the tap water for the same things. If the tap water is ok, do a partial water change. Add some fresh activated carbon to the filter. That will help remove poisons/toxins if they are involved. Add some pond salt at 0.05%. Beyond that, it would require a pond store or pond club person or someone to examine the fish and do more extensive tests on the water.

Have you put in any new rocks or ornamental stuff? Any new plants? I'm just brainstorming for something poisionous. Are all your plants TOTALLY healthy, as in no wilting, contining with leaf growth, blooming. Just a thought.

After I lost my first fish that I had for years I totally got rid of everything plants rocks, pump, everything! then drained it completely, cleaned it out...rinsed it over and over..I filled it up with fresh water put pond starter and stuff to remove the chlorine, and ammonia, and good bacteria stuff..waited three days then put fish in..The first ones lived for about four days so I added 2 nore from another place .That is when they started dying..The first ones then the last two...
All within three days...Now My pump did stop on me and they went without a pump for a few days and it did get warm here in the 90's but the water never felt very warm...So now I started over again I have cleaned it and out all the stuff back in ..Fixin to order some plants and then in about two weeks I will try some fish again...
Like i said I have had a pond for 10 years and never had this trouble...and all I have ever done was put water in and chlorine stuff in it...
I honestly think my old fish died cause of the temp change we had.. It was Easter and it was in the 80's one day and dropped to 28 that night....I sure miss my babies...

just my 2 cents but my hubby is the manager of our local water company and he treats water.you may want to call you water plant and see if they have swapped chemicals around or increassed some,we had this problem where they had added a chemical because they water was cloudy from a rainn and it killed my aquarium fish so you may want to try that if you have city water.maybe they can help or test the water for you for everything possible our water plant will test pond water or well water for 5$ to see what problems it has and there are tests they do you would never thinkof they can test the oxygen also

I agree. It would be a good idea to find out if the water company has made any changes or there are any changes in the water recently. Ask if they've changed the amount or type of chemicals used for chlorination and fluorination.

Well had my water tested..My ph level was real low....so got it right and adding fish today ...Wish me luck!!!!

Good Luck!!! :D :D

What was the well water's pH? Did they test it both before and after aeration? It normally goes up after aeration as the carbon dioxide is driven off (carbonic acid lowers the pH).

If you'll notice my earlier postings, in the first response, I included damage from low pH as a possibility and suggested testing for it a few times. When problems arise, it's good to have test kits around for the basics and check those first. It can save time, money, and heartache over lost fish to know sooner what is wrong.

Good luck with the new fish!

Robyn, what can cause the PH to drop so suddenly like that? This whole thread put a scare in to me, what with Dianne having had a pond for 10 years then all of a sudden losing all her fish.

Dianne, suggest you grab a little ph test kit at the aquarium store, at a minimum, to try and keep and eye on it.

Mary Anne

Not being Diane, I don't know if she regularly tested the pH, hardness, and alkalinity which are all interrelated. It may be that the pH was low before the fish deaths, or it gradually went down. That's why we should all be testing our pond water more often than we do so we can catch changes before they become a problem.

The pH may crash in a pond for a number of reasons. Here are some thoughts that come to mind.

1. Heavy rain - Rain has no hardness or alkalinity and tends to be acidic.

2. Poisoning - Especially with things acidic in nature.

3. Too many plants and/or algae - These can cause pH fluctuations in the pond with the pH being lowest at dawn and higher at dusk. If the pond is suffocating in plants and/or algae, the pH may drop down dangerously in the morning. If, on top of that, the alkalinity is low, the water's pH won't be buffered making the pH swings larger. I don't know what time of the day Diane had her pond water tested.

4. Change in the source water - If the water company gets their water from a different location or changes what chemicals that they add to the water, then the tap water itself may change its pH. I have a well so there is less chance of a change but prolonged drought may alter the water's chemistry some.

I suggest testing your pond's water once a week at the same time and day. You'll learn what's normal and can make adjustments if needed. If you ever find a problem, test the tap water as well. If it's better, then water changes help. If it's not, water changes may make things worse. I wish I had the time to do more testing myself on my ponds!

Hi Diannemc

So sorry to hear about your pond.
Just want to wish you luck with it and keep us up to date.

swampview