Bad smell from new pond

[Londonpondtrier]

Two weeks ago I installed a 60cm container pond in our (very small) back yard. I put in four water plants, some sub surface oxygenating plants, a net bag of organic barley flakes to keep
down algae, and a small solar powered fountain. As it had not rained for ages when the pond arrived and our local tap water is heavily treated with chemicals, I initially put in about 30 litres of “mountain water” ie bottled drinking water from the Scottish highlands which isn’t chemically treated. Right now it’s probably 70% that, and 30% rainwater.

I noticed within a day or two that there was a lot of bubbles/scum forming on top
of the pond when the fountain ran. After about a week, I noticed a bad sewage-y smell from the pond, and a thick circle of brown scum forming overnight, directly above where the bag of barley flakes was. I removed the bag and chucked it away and scooped out all the brown scum I could.

There is now no more bubbly scum, just a very very thin layer of transparent brown residue on the pond that forms when the fountain does not run.

However the smell has not gone away. It is particularly bad when the fountain runs. We have a very small backyard so there is no escaping it.

The water otherwise appears to be and the surface plants look OK. I have worked very hard to keep debris out of the pond so I don’t think it can be that.

Does anyone have any suggestions for what caused/is causing this smell please, and what I could do about it?

thank you





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[addy1]

My only guess is it was the barley rotting but I can't be sure.
Since you have no fish I would empty and refill with tap water, the plants will do fine with it

 

[mrsclem]

Agree with @addy1 , tap water is fine as long as you don't have fish. What are your plants in- soil? The barley is probably the reason for the smell. Also, your fountian is only running part time so it's possible the water is getting stagnant.

 

[Londonpondtrier]

Agree with @addy1 , tap water is fine as long as you don't have fish. What are your plants in- soil? The barley is probably the reason for the smell. Also, your fountian is only running part time so it's possible the water is getting stagnant.

The plants are in a kind of sandy soil in mesh baskets.

 

[Lisak1]

That's a lot going on in a very small pond! I agree with @addy1 - your barley straw was rotting and causing the stink most likely. Start over with fresh water and keep it simple!

 

[Londonpondtrier]

Is it possible that the water might have a lot of iron content in it, and that’s causing the smell? I have read somewhere else in this forum that bacteria feed on iron.

I did think I was keeping it simple with only four tiny plants and no fish!

 

[Mike in Vermont]

The brown scum you are describing is from vegetation rotting in the water. In this case, most likely the Barley.

 

[Lisak1]

Is it possible that the water might have a lot of iron content in it, and that’s causing the smell? I have read somewhere else in this forum that bacteria feed on iron.

I did think I was keeping it simple with only four tiny plants and no fish!

I meant the barley straw and bottled water... you're fighting problems you don't even have yet. A pond shouldn't bring a plan of attack with it.

All ponds go through a maturing process - algae growth its one of the stages. And in fact a healthy pond has a good supply of algae in it all the time, but a new pond might get an overgrowth of algae as it works to find it's balance.

Use your tap water - I'm sure it's safe for your plants. I've never heard that bacteria feeds on iron, but in any case the bacteria you want to encourage in your pond won't smell bad. What you're describing is the smell of anaerobic bacteria from something rotting. And that's exactly how that barley straw works, by the way - by rotting in your pond. The theory is it puts off a chemical that discourages algae growth as it decay. But in your case, you don't even HAVE algae yet.

You may find your plants struggle in your pond without fish - they are part of the pond trifecta: water, plants, fish. They all need each other for an eco-balanced pond. If you don't want any fish, you might consider fertilizing the plants.

 

[Londonpondtrier]

I did ask on Amazon to see if anyone else who had bought the barley flakes for a small pond had experienced that smell. So far have had one response from someone who said no, no smell.

 

[Londonpondtrier]

Use your tap water - I'm sure it's safe for your plants. I've never heard that bacteria feeds on iron, but in any case the bacteria you want to encourage in your pond won't smell bad. What you're describing is the smell of anaerobic bacteria from something rotting. And that's exactly how that barley straw works, by the way - by rotting in your pond. The theory is it puts off a chemical that discourages algae growth as it decay. But in your case, you don't even HAVE algae yet.

Here’s the link on this forum where someone talks about iron in the water and bad smells…

Pond smells like sewage

Hello, I manage two concrete ponds. I've installed a plant filter in one that keeps the water crystal clear and healthy for everything living in there, but every time I try on the other one the plants fail to thrive and the water turns brown and ends up smelling like sewage. I've tested all...

www.gardenpondforum.com

 

[j.w]

@Londonpondtrier

 

[Mmathis]

Hello and welcome. I tend to agree with the other comments. Can you post some pictures of your pond?

 

[Lisak1]

Here’s the link on this forum where someone talks about iron in the water and bad smells…

Pond smells like sewage

Hello, I manage two concrete ponds. I've installed a plant filter in one that keeps the water crystal clear and healthy for everything living in there, but every time I try on the other one the plants fail to thrive and the water turns brown and ends up smelling like sewage. I've tested all...

www.gardenpondforum.com

I seriously doubt you have an overabundance of iron in your tiny pond that's creating a smel, especially with bottled water. Are you seeing other signs of high iron? The other things you describe - brown foamy scum - all point to rotting organic material. Other people may notice the odor if they are using the barley straw in a much larger pond.

But anyway - change the water. Problem solved.

 

[HARO]

We have a high iron content in our well water, and it DOES have an unpleasant odour. I wouldn't say it smelled like sewage, but that might depend on the amount present. Having said that, I doubt that would be your problem since iron is USUALLY only present in well water, so I'll have to go with the barley straw. If you still want the benefits of the barley, I would recommend the liquid extract... it doesn't have to go through the rotting process.
John

 

[G Massam]

Hi an welcome Londonpondtrier, have you had a conciderable amount of rain lately, you may have a drain backing up? Just saying