rain water and dead fish?

[Douglas]

Hello fellow pond mates,

I am fairly new to keeping a proper pond. I do have experience with aquariums.

I really need some insight on what is happening to my pond.

I decided to make a 40 gallon pond outside (filter, floating plants, airstones, etc...) since the start of April. Just couple weeks later I bought four goldfish. They were doing fine for a week and then it rained. My pond sits right under the gutter of my house roof, so some rain water drips into the pond when it rains. But I noticed that after it rained, my goldfish all were gasping for air and they had what it seemed to be a thick white slime coat covering their bodies and eyes.
I was able to speed up my nitrogen cycle because of using filter floss that was in my aquarium filters. I have been testing the ammonia, nitrite, and nitrate and all are zero with nitrate being around 2-3 ppm. I did not test PH. Which will be my next thing to do.

The goldfishes died shortly after that and I assumed maybe they were just stressed from encountering water tapping the surface of their water constantly. my water readings were still reading good. Therefore I got four more goldfish. And WHALLAH it rained the next week and the same thing happened.

This leads me to think that something about the rain is causing my fish to die.
- loss of electrolytes due to rain having little nutrients in it therefore the chemical balance in my fish were causing them to slime up a coat.
- rain water acid
- harmful metal from gutter (although I did have a 20 gallon bucket for 2 years with minnows and the rain from the gutter never seemed to affect them).

If anyone knows or can point me a direction to a solution please let me know. I have built an acrylic glass that sits 2.5 feet above my pond now to redirect the falling rain and not into my pond. But I do not want to keep buying fish to test these theories.

Thank you, Douglas

 

[Waterbug]

When it comes to rain my first thought is the KH level. Rain does have a very low pH, generally in the 4.5 range but can get down to the low 2's for thunderstorms which is in the vinegar range. So say a pond is pH 8 but low KH (buffer). A lot of rain water can consume what buffer is there and then the pH goes down fast. That can trigger a slime coat.

I'm not a fan of measuring pH in general because that only tells you what the water is at that moment. By measuring KH and keeping that up it tells me what the pH is going to be tomorrow and beyond, stable. If I buffer with baking soda and KH is high I know the pH is going to be around 8.3 and stay there. Plus, when KH is very low, no buffering, then pH is not easy to measure because the measurement can swing wildly due to so few ions floating around.

Measuring KH and buffering with baking soda just keeps things super simple. It's almost impossible to add too much baking soda as the only factor really is the salt content building too much, but a person would have to be adding about 100 times more baking soda than needed. That's a hard mistake to make.

Some do suggest all kinds of things for buffering like limestone, oyster shell, plaster, egg shells, you named it. But all these things take time to dissolve. In your case if you'd had a bunch of oyster shells in the pond a pH crash still would have happened and maybe a day later pH would have recovered. Fish can't wait that long. Baking soda is already dissolved and ready for reaction basically instantly. But I think many people just like the idea of adding shells and such.

But, like you mentioned, could be other chemistry issues too and is likely a combination of different chemistry issues. Even temperature change. Just a lot of different things changing. For a 40 gal pond it doesn't take much.

I would not suspect the metal gutters either unless they were copper which I assume not.

 

[j.w]

@Douglas
So sorry to hear this is happening and do hope you can figure it all out so it does not happen again. I've had gutter water run into a previous pond I once had and we here in Washington get rain quite often all through the year. Never had any issues w/the gutter water running through a metal gutter straight into the pond and that pond was up and running for several years before I decided I needed a bigger pond in a better spot. I'm wondering if it's not the gutters but it's the actuall rain, maybe acid rain which I've heard can kill fish. Perhaps if it is acidic and so much rain is concentrated when entering your pond it could be killing the fish. Is there a lot of gunk in the gutters as perhaps that could be contributing to the problem also.
Here is an article from a news report from our area that may explain it better: https://education.seattlepi.com/acid-rain-affect-lakes-5961.html

 

[Douglas]

@Waterbug
Thank you for your insight. I am going to go get something to measure the kh. I have oyster sells in my aquarium filters to add buffer so I guess I should add some into my pond filter as well.

@j.w
Thank you. I couldn't possibly think its my gutters as well. I am going to check my gutters and clean them out. At least with that I can rule out for sure its not gutter rain drops. Guess I should also check the rain water ph and kh as well when it rains again.

 

[JamieB]

Another thing to point out, a 40 gallon will have tempature changes faster than a bigger pond. And for 4 full grown goldfish, it’ll be too small. Unless you’re planning a bigger pond, it’s not going to be enough to support 4 goldfish for long. I’m not sure about fancy tails, as they are smaller and stay smaller, but the standard types need 60-100 gallons each once full grown. A larger pond will also provide more buffer for rain water.

 

[poconojoe]

Some kind of contamination from your roof shingles?
40 gallons is quite small for fish load. And the smaller size means very quick changes. It doesn't take much for a drastic change with that little amount of water.

 

[Waterbug]

@Waterbug
Thank you for your insight. I am going to go get something to measure the kh. I have oyster sells in my aquarium filters to add buffer so I guess I should add some into my pond filter as well.

You're welcome.

As I said, specifically, oyster sells will do nothing to solve this issue. They're really very poor pH buffers especially for this issue. They're very, very slow to stabilize pH. That's OK in some ponds that are inherently stable whether any buffer is used or not. For example in large ponds that get regular water changes using water that has good KH to begin with. Those pond owners are free to get on the internet and say how great oyster shells are. They give credit to the oyster shells because that was their idea, but the credit should go to the water changes which they don't realize is doing the buffering.

I get it, this is a hobby, people should have fun and many people like adding stuff to their pond...so by all means add oyster shells, they will do no harm. But consider also adding a fast reacting buffer like baking soda to solve the actual problem. You get stable pH and you can still tell people it's the oyster shells doing it. Win - win.

Unfortunately this does remind me why I stopped posting here awhile back. It makes me feel a bit responsible when users pick out bits and pieces of info and my info is used to make things worse. I'm not blaming users, it's just a dynamic created by these online forums. They're really more for entertainment and should only be used for entertainment. I think I do more harm by posting than help. Sorry.

 

[Douglas]

I added crushed coral into the pond filter just to keep something there for some kind of buffering. I am reading that about 1 teaspoon of baking soda per 10 gallons? Is that around the ballpark ?

 

[addy1]

Our water is very soft, very acidic. Until I used crushed oyster shells the KH did not increase, the ph was not stable. I added around 100 lbs the first year and let it run for a year before I added more fish. The first fish died due to the low ph of the water. Now it is very stable even with our acidic rain, our acidic well water. I do not do water changes, water is added when it rains or if I need to when the level drops during the summer.

When I drained my hot tub pond and refilled it, trying to catch a fish, the ph was under 6, KH below 30. I added a small bag of crushed oyster shells, including the dust, within a day the ph was fine and the KH climbed to a acceptable level. The added fish are health.

For me they work and work well.

Baking soda never made the ph stable. I went though bags of it.

 

[JamieB]

Perhaps it’s a matter of how acidic the water is for if the shells or baking soda works. I’m lucky, my well water is naturally high kh, with a ph of around 8. But if you think on it, a higher acidity would break the shells down faster, and use up the baking soda fast, and require more baking soda. I’ve never had to add baking soda to my pond or aquariums, I have tried the reverse, of adding an acid to drop ph. Quick fixes didn’t last long, and even drops from the store didn’t do great, so I just had to let the fish adapt to my natural ph.

 

[addy1]

so I just had to let the fish adapt to my natural ph.

Wish I could but it is putting them into a acid bath, we measure 5.3 using a ph meter.
One reason I don't do water changes, the fish would not be able to handle a large change over.
My pond is mature enough it handles additional water adds without swinging the ph.

 

[Stephen Noble]

Another thing to point out, a 40 gallon will have tempature changes faster than a bigger pond. And for 4 full grown goldfish, it’ll be too small. Unless you’re planning a bigger pond, it’s not going to be enough to support 4 goldfish for long. I’m not sure about fancy tails, as they are smaller and stay smaller, but the standard types need 60-100 gallons each once full grown. A larger pond will also provide more buffer for rain water.

JamieB is spot on. 40 gallons is only large enough for temporary housing of one, small goldfish. What type of pond is it? Could you please post a picture?

 

[JamieB]

Wish I could but it is putting them into a acid bath, we measure 5.3 using a ph meter.
One reason I don't do water changes, the fish would not be able to handle a large change over.
My pond is mature enough it handles additional water adds without swinging the ph.

Water like that does need adjustment, way outside their range. Mines just a little high for their normal range

 

[bettasngoldfish]

@Waterbug

I have always enjoyed reading your posts. You have so much knowledge and information to share. It would be a shame for you to quit participating again.

 

[CometKeith]

Hello fellow pond mates,

I am fairly new to keeping a proper pond. I do have experience with aquariums.

I really need some insight on what is happening to my pond.

I decided to make a 40 gallon pond outside (filter, floating plants, airstones, etc...) since the start of April. Just couple weeks later I bought four goldfish. They were doing fine for a week and then it rained. My pond sits right under the gutter of my house roof, so some rain water drips into the pond when it rains. But I noticed that after it rained, my goldfish all were gasping for air and they had what it seemed to be a thick white slime coat covering their bodies and eyes.
I was able to speed up my nitrogen cycle because of using filter floss that was in my aquarium filters. I have been testing the ammonia, nitrite, and nitrate and all are zero with nitrate being around 2-3 ppm. I did not test PH. Which will be my next thing to do.

The goldfishes died shortly after that and I assumed maybe they were just stressed from encountering water tapping the surface of their water constantly. my water readings were still reading good. Therefore I got four more goldfish. And WHALLAH it rained the next week and the same thing happened.

This leads me to think that something about the rain is causing my fish to die.
- loss of electrolytes due to rain having little nutrients in it therefore the chemical balance in my fish were causing them to slime up a coat.
- rain water acid
- harmful metal from gutter (although I did have a 20 gallon bucket for 2 years with minnows and the rain from the gutter never seemed to affect them).

If anyone knows or can point me a direction to a solution please let me know. I have built an acrylic glass that sits 2.5 feet above my pond now to redirect the falling rain and not into my pond. But I do not want to keep buying fish to test these theories.

Thank you, Douglas

Hi Douglass. Pond keeping is an empirical science because everyone's pond is slightly different and sometime what works for one person doesn't always work someone else because the conditions are different. Think about it... If you pond and fish are doing well why would you let your gutter fill the pond with rain water from the downspout? The concentrations of dissolved O2, PH, and many other things are different than your pond and why would you want to do that? For starters I would move the gutter or the pond so this doesn't happen again and problem solved! Good luck with your pond and fish.

On another topic: Re old members coming back. Usually there was a reason they left...