Goldfish dying after cleaning pond.

[MikeW]

I have had a goldfish pond in my back yard since 1978. Every couple of years I drain it and clean out the old layer of oak leaves and muck and refill with fresh water. My fish were healthy and I changed the water like I normally do. I usually siphon existing pond water into a child wading pool and put in a aerator pump and move the fish to the pool and the fish seemed happy after the move. After cleaning the pond I treated with a pond anti-chlorine and water stabilizer product that I purchased in the pet store for fish ponds. I then floated the fish in plastic bags until the water temp was the same in the bags as the pond (40 minutes). I released them back into the cleaned pond and within a few hours they seemed sick and lethargic. Two days later I found 8 of my fish dead in the pond and the remaining 10 not eating and lethargic. I have done this many times the same way using the same wading pool, etc and the fish always seemed happy with their clean pond. The only difference I know was I used a different pond anti-chlorine product that I had purchased a couple of years ago. Does anyone know what could have caused this? Do anti-chlorine products go bad after a couple of years of storage in the basement?

 

[mrsclem]

Check the label on the product to see If there is an expiration date. Liquid pond chemicals can go bad or lose their effectiveness.

 

[MikeW]

Check the label on the product to see If there is an expiration date. Liquid pond chemicals can go bad or lose their effectiveness.

I checked but there is no expiration date. Just went out and found 2 more fish dead.

 

[ChrisP]

Ugh, that suck.

It could also be that your municipality changed their recipe for chlorination. 'Round these parts they really dump in chloranimine in the early spring when the snow melts.

 

[MikeW]

I checked but there is no expiration date. Just went out and found 2 more fish dead.

Decided to pump out most of the water (900 or so gallons) and refill the pond adding new chlorine remover that I purchased today. So far the few fish I have left are looking better. Time will tell if it works.

 

[j.w]

Every time you change all that water you make it so the pond has to go through a cycle of getting the water right for the fish all over again. Fish don't like that and it shocks them.

 

[CometKeith]

I have had a goldfish pond in my back yard since 1978. Every couple of years I drain it and clean out the old layer of oak leaves and muck and refill with fresh water. My fish were healthy and I changed the water like I normally do. I usually siphon existing pond water into a child wading pool and put in a aerator pump and move the fish to the pool and the fish seemed happy after the move. After cleaning the pond I treated with a pond anti-chlorine and water stabilizer product that I purchased in the pet store for fish ponds. I then floated the fish in plastic bags until the water temp was the same in the bags as the pond (40 minutes). I released them back into the cleaned pond and within a few hours they seemed sick and lethargic. Two days later I found 8 of my fish dead in the pond and the remaining 10 not eating and lethargic. I have done this many times the same way using the same wading pool, etc and the fish always seemed happy with their clean pond. The only difference I know was I used a different pond anti-chlorine product that I had purchased a couple of years ago. Does anyone know what could have caused this? Do anti-chlorine products go bad after a couple of years of storage in the basement?

Hi Mike. I'm so sorry about your fish. I am not familiar with any disease that will so quickly kill fish so I'm guessing it is the declor you used was bad. Lack of O2 they can utilize is very deadly and will quickly kill fish. Did you have a chance to inspect any of the dead fish and if so could you notice anything wrong with them? Also were the dead fish found in the early morning? That is when O2 levels are at the lowest. If the fish didn't appear to have disease then I would say with a high degree of certainty it was the declor and the chlorine burned their gills. I know you have been doing it this way for a long time and it works for you, but anytime you do a wholesale change of water you are at a bigger risk of changing some key element of the pond water that may hurt your fish.

 

[MikeW]

Thanks for the info. I believe you are right about the anti-chlor. I bought it at Lowe’s about 3 or 4 years ago and had never used it. There was no expiration date so I assumed it was still OK. Yesterday I pumped out most of the water (around 900 gallons from a pond that holds about 1000 gallons) and replaced the water adding new anti-chlorine as the water entered the pond. Evidently it worked because the few remaining fish seem fine this morning and are swimming all around the pond. I noticed the new bottle of anti-chlorine that I purchased at the pet store does have an expiration date.

 

[Lisak1]

Let's hope that was it. It does seem weird that something that expired would suddenly be toxic - you'd think it would simply be ineffective, but it is a chemical so anything is possible.

 

[Kathryn]

Thanks for the info. I believe you are right about the anti-chlor. I bought it at Lowe’s about 3 or 4 years ago and had never used it. There was no expiration date so I assumed it was still OK. Yesterday I pumped out most of the water (around 900 gallons from a pond that holds about 1000 gallons) and replaced the water adding new anti-chlorine as the water entered the pond. Evidently it worked because the few remaining fish seem fine this morning and are swimming all around the pond. I noticed the new bottle of anti-chlorine that I purchased at the pet store does have an expiration date.

Thank goodness!!

 

[Faebinder]

Fish death after a water change is almost always chlorine/chloramine related. It's classic at this point.

 

[csdude55]

The last time that I had a major loss like that, I bought a water test kit at Lowes and discovered that my water had a high level of copper and iron in it. It was literally burning the fish, I could see marks all over them!

I bought a whole house filter and plugged it in before hose spigot, and now everything comes out more pure. Mine is well water, though, so I don't have to worry about municipal additives like chlorine. But still, a water test kit for $15 or so might save you a lot of stress... and realistically, it's good to know what's in the water that you're drinking and bathing in, too.

 

[Lotus]

I wonder whether it is better not scraping the bottom of the pond, and leave all what accumulated there as the plants seem to like it and that way never change all the water. I have a pond like this, nothing done with it for 10 years at all, only re-filled with tap water when it evaporated, black bottom and the fish was fine. Then I bought a pump, got most of the water out, put in new tap water probebly 1/3 of the pond and all my fish died.

 

[Lisak1]

@Lotus this is an older post but I’ll chime in - it can definitely upset the balance of a pond to clean and add new water. It’s possible there was toxic gas trapped in the muck in the bottom or the water you added was chlorinated or the pH change shocked the fish. Always good to proceed cautiously.

 

[GBBUDD]

Thanks for the info. I believe you are right about the anti-chlor. I bought it at Lowe’s about 3 or 4 years ago and had never used it. There was no expiration date so I assumed it was still OK. Yesterday I pumped out most of the water (around 900 gallons from a pond that holds about 1000 gallons) and replaced the water adding new anti-chlorine as the water entered the pond. Evidently it worked because the few remaining fish seem fine this morning and are swimming all around the pond. I noticed the new bottle of anti-chlorine that I purchased at the pet store does have an expiration date.

First of all I would never use any products from. A non fish box store or Wal-Mart. That's sales I'm a bottle to me and no one there has a value who what where or when.
If you did a full water change and your in or effected by all the fires in Canada the odds are good your city has had to boost chemicals to " get the water drinkable".