# Help with garden pond



## ZEROPILOT (Mar 26, 2019)

My "new"fish pond has been up and running now for quite a while. The water has always been crystal clear and my fish have been thriving.
That all changed this morning.
This morning I went out to feed the fish and found a lot of smelly, bubbly clumps of goo floating on the surface. Covering about 70% of the surface.
I looked for dead fish. Dead frogs. Dead rats and found nothing. But a closer inspection showed that even though the filtration seemed to be working ok. The UV sterilizer had burned out.
The fish are not very active either.
I'll be doing some water chemistry tests in a while. But right now I'm replacing the UV sterilizer and a lot of the water.
There is a waterfall. But I've just added two fountains for even more oxygen. I've also replaced a lot of the filter media.
Do any of you that keep ponds think that this was just caused by some type of organic or algae "bloom" caused by my lack of UV?
So far, my fish have not died.
I'm anxious to see what it looks like in 24 hours.


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## Markw84 (Mar 26, 2019)

Bubbly surface is normally a sign of dying plant matter, and normally algae. IF you use an algaecide in the pond, you will see this forming for a day or two after with the algae dying. So an algae bloom followed by a change in water temps can start this cycle as well. Also, build up of debris in the bottom of the pond, or trapped between rocks, etc. also can suddenly reach a point of higher nitrate levels and you will see this as well. IF your UV filter was the main issue, you would have seen a drop in water clarity and the signs of an algae bloom first.

Be sure there are not areas in your pond that are trapping debris. That is a main cause of this in established ponds. Especially as the temps start to warm up again in spring.

The biggest difference in overall water quality I see is with proper aeration. Assuming you have a good working filter system, the next most important thing in a good pond environment is good aeration. I have big and vigorous waterfalls, with plenty of bubbling and churning, but it was the addition of a good aerator and pond aeration pads that made by far the biggest difference.


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## ZEROPILOT (Mar 26, 2019)

Markw84 said:


> Bubbly surface is normally a sign of dying plant matter, and normally algae. IF you use an algaecide in the pond, you will see this forming for a day or two after with the algae dying. So an algae bloom followed by a change in water temps can start this cycle as well. Also, build up of debris in the bottom of the pond, or trapped between rocks, etc. also can suddenly reach a point of higher nitrate levels and you will see this as well. IF your UV filter was the main issue, you would have seen a drop in water clarity and the signs of an algae bloom first.
> 
> Be sure there are not areas in your pond that are trapping debris. That is a main cause of this in established ponds. Especially as the temps start to warm up again in spring.
> 
> The biggest difference in overall water quality I see is with proper aeration. Assuming you have a good working filter system, the next most important thing in a good pond environment is good aeration. I have big and vigorous waterfalls, with plenty of bubbling and churning, but it was the addition of a good aerator and pond aeration pads that made by far the biggest difference.


Thank you.
I just did another partial water change.
This time I overfilled the pond so that the surface scum drained off. I don't want to do any more because I don't want to further stress the fish.
The outside temperature has been in the lower 80s constantly. The water HAS looked a little cloudy for about a week or so, but I chalked that up to it needing a filter clean out. When I did the filter cleaning I did not inspect the UV sterilizer. It glows. But you can really only see it glowing at night.


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## Redfool (Mar 26, 2019)

A surface skimming biofilter along with your UV sterilizer is best for ponds. Oak pollen and flowers are starting to turn my pond a tannic tea brown. Overflowing your pond will act as a skimmer. Also check for Cuban Tree frog eggs, they can turn a small pond nasty real quick. Slow down feeding till water quality comes up. If a lot of new water is added be sure to also add some chloramine neutralizer.


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## ZEROPILOT (Mar 26, 2019)

Redfool said:


> A surface skimming biofilter along with your UV sterilizer is best for ponds. Oak pollen and flowers are starting to turn my pond a tannic tea brown. Overflowing your pond will act as a skimmer. Also check for Cuban Tree frog eggs, they can turn a small pond nasty real quick. Slow down feeding till water quality comes up. If a lot of new water is added be sure to also add some chloramine neutralizer.


Unfortunately when I was designing and building the pond, I opted to not go with a skimmer. Now because it has a stone and cement border, adding one would be hard to do.
My original design had a skimmer as the pond pump inlet.
Until this morning, I've never had any scum or debris to skin off. And because it's in a semi enclosed area, there are no leaves, etc and only indirect sunlight.


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## ZEROPILOT (Mar 26, 2019)

I did use Chlorine and Cloramine remover.
I buy it by the gallon.


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## Markw84 (Mar 26, 2019)

Another thought - did your Koi spawn? This time of year if big enough, they will spawn and that puts a huge strain on the filter. When my koi spawn, I fight getting thing back stabilized for over a week. My females are over 26" and just one of them will dump close to 500,000 eggs when spawning. That's a lot of organic matter!


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## ZEROPILOT (Mar 26, 2019)

Markw84 said:


> Another thought - did your Koi spawn? This time of year if big enough, they will spawn and that puts a huge strain on the filter. When my koi spawn, I fight getting thing back stabilized for over a week. My females are over 26" and just one of them will dump close to 500,000 eggs when spawning. That's a lot of organic matter!


Maybe
Would they be along the sides and bottom?


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## ZEROPILOT (Mar 27, 2019)

This morning the water is a bit clearer and there are no slimy chunks floating.
However, there is even more foam. Some bubbles by the waterfall are large. Like soap bubbles.
The fish are a bit more active and ate food this morning. But not with their usual enthusiasm.


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## ZEROPILOT (Mar 27, 2019)

The readings are:
Temperature is a steady 78.

Ammonia is a trace. Less than 0.25 PM

PH is a bit low at 6.8. I have just buffered it a bit with some baking soda.

Nitrates are 0

Nitrites are elevated. About 3.5 PM I have added more aeration and raised the pump volume to maximum. (2,000 gph)
I've also replaced the UV sterilizer. But I'm wondering if I should be using it until the Nitrates go back down.
It DOES SEEM to be helping with the overall water quality.


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## ZEROPILOT (Mar 27, 2019)

One other thing.
My back patio has a corrugated steel roof. When it rains, water from the roof does enter the pond.
Since the roof is about 400sf. Anything that lands on the roof....Pollen, etc. Would and could drain into the pond in large quantities. This has never been an issue before. But I'm keeping it in mind. I looked up there with a ladder and saw nothing out of place.


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## ZEROPILOT (Mar 27, 2019)

The best guess on the Garden Pond Forum is that foam and strong smell mean that one or more Koi has spawned.
And they are in the process of eating the eggs.
It would also give me that slight bump in ammonia.
Same as @Markw84 said.


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## KarenSoCal (Mar 28, 2019)

You mentioned in post 1 that you replaced a lot of your filter media and water. It seems you got rid of nitrates with your water change. Replacing lots of media could have messed up your nitrogen cycle, bumping the ammonia up, along with nitrites. In a couple days your cycle should complete, and you'll have nitrates again.


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## ZEROPILOT (Mar 28, 2019)

Both the filter and the waterfall are media filled.
I normally replace just one of the two filter pads in the filter and never, ever clean the bio balls or the filter housing.
Today, the fish are splashing around as soon as they see me and the water looks better.
I'll do another test tomorrow


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## KarenSoCal (Mar 28, 2019)

ZEROPILOT said:


> Both the filter and the waterfall are media filled.
> I normally replace just one of the two filter pads in the filter and never, ever clean the bio balls or the filter housing.
> Today, the fish are splashing around as soon as they see me and the water looks better.
> I'll do another test tomorrow


Very good! I should have known you would know that! [emoji16]


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## ZEROPILOT (Mar 28, 2019)

KarenSoCal said:


> Very good! I should have known you would know that! [emoji16]


Actually I appreciate the help


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## ZEROPILOT (Mar 29, 2019)

Thanks for the help.
Everything looks normal this afternoon.
The water is clear and there's no foam.
The fish are all very active and I didn't lose any fish.
The water parameters are also falling back into the normal, safe range.
I guess it's over.


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