Goldfish dying in my pond

[roger dias]

I have a backyard pond about 10 feet in diameter, a foot and a half deep at start to 2 1/2 feet in the center, then two feet, then one a half feet around perimeter. It is vegetated with pond lily and another plant that is 5 foot tall. I have a water pump pumped up 12 feet to a filter, then the water comes back down.
All I have are goldfish and they are dying regularly. all dead ones floating. Fresh water has been added regularly.
the two plants cover 50 percent of the pond surface.

Fish look healthy when I put them in. Then they die in a short period of time. Fresh water added every two weeks.
I wonder if the plants are involved in the death of these fish. I only have goldfish in the pond.
In the past I've had the goldfish last through the winter.
I am on Cape Cod Massachusetts.

 

[mrsclem]

Hello and welcome Roger. Sorry you are losing your fish. You are adding fresh water every week, why? Do you have a leak? Well water or city water and if city water , are you treating it for chlorine and chloramines?
How many fish and how large are they? Doubt that the plants are to blame, is it possible there are chemicals getting into the pond?

 

[j.w]

@roger dias
I would wonder too about chlorine/chloramine in the city water or some contaminate entering your pond. Wondering what the ph is in your water?
What do the fish look like when you find them dead? Do you have a test kit for your water?

 

[Lisak1]

Welcome @roger dias . I agree with @mrsclem - it's not the plants. How do they fish look when they are dead? And are they showing symptoms before they die? Gasping or staying near the bottom of the pond? Scraping or flashing? Are they bloated? Clear eyes? Red gills?

 

[CometKeith]

Hi. i'm sorry about your fish. When fish die in the summer when they previously looked fine the culprit most of the time is lack of dissolved O2. This can because by damage to their gills from chlorinated water or just a lack of O2. Typically it is worse in the early morning hours when O2 is at it's lowest and the largest fish suffer the most because they need the most O2. I hope this helps.

 

[Mmathis]

How many fish do you have, and how big are they?

 

[Netfrog]

What kind of rocks/stones are you using? If using limestone or similar type material, your pH level may be off balanced.

 

[Netfrog]

I have a hot tub pond (approx. 1000l/300gal and 30 inches deep) with a dozen goldfish (shubunkins and sarassas). It has 75% coverage (one lily, water hyacinths, salvinia and below hornwort). I pump the water through a pressure filter that has a uv light which in turn flows through a waterfall. On top of this, I added an air bubbler under the waterfall. This is my fourth year with this setup and so far have not lost a fish. I'm hoping that you can glean some info from my setup to help you.

 

[CometKeith]

I have a hot tub pond (approx. 1000l/300gal and 30 inches deep) with a dozen goldfish (shubunkins and sarassas). It has 75% coverage (one lily, water hyacinths, salvinia and below hornwort). I pump the water through a pressure filter that has a uv light which in turn flows through a waterfall. On top of this, I added an air bubbler under the waterfall. This is my fourth year with this setup and so far have not lost a fish. I'm hoping that you can glean some info from my setup to help you.

Hi. It's really hard to help people without all the proper information. There were a few questions people had..... are they showing symptoms of disease? If not then most likely the culprit is a lack of dissolved oxygen. In my own pond I have 2 pumps shooting water, one air stone keeping a continual jet of bobbles, and my filter and external pump releasing water into the pond. You can never have enough water movement. If they are showing signs of disease then your bio-filtration is not properly sized for your pond or it is not working properly. I hope this helps.

 

[Netfrog]

Also, you should introduce beneficial bacteria starting in the spring to help break down decaying debris. As others mentioned, make sure the water you introduce or add to your pond has been declorinated.

 

[Lisak1]

Also, you should introduce beneficial bacteria starting in the spring to help break down decaying debris.

This is advice that I hear repeated frequently, but I would suggest that it's far better to remove the decaying debris with a net than it is to allow it to break down in the pond. I mean, it WILL break down - bottled bacteria or no - but the result of that breaking down leads to undesirable results like an overgrowth of algae. As natural as we try to make our ponds look we have to acknowledge that they are not 100% natural - a natural pond doesn't have an EPDM liner and is therefore able to break down bottom debris.

Back to the regularly scheduled post! @roger dias are you still here?

 

[Sisha]

Hey, Roger, sorry to hear about your goldies. Have you checked your ammonia levels? High ammonia can kill real quick. A circulating pump won't get rid of ammonia, only bacteria can do that. I had that happen years ago. I built a biofilter and haven't lost a fish since except from predators. I hope you find the problem.