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I have recently had a natural pond created in my garden, which has some lovely plants in it, which are now flowering and look tremendous.

Over the week or so Ive noticed that  what I can only describe as green slime floating in the pond around the plants and on the bottom of the pond.

I have started to remove it with a fishing net, is this correct and is there some product I can buy to keep the pond clear or is it best just to get some more oxygenated plants to assist?

Many thanks





If it's green algae, I can recommend Blagdon Barley Straw extract - you can get it on line or from most GCs.  

If it's blanket weed the extract seems to help keep it down, but I also use a bamboo cane and twirl it around a bit like making candyfloss and pull it out and leave it on the bank so that any inhabitants to find their way back to the water. 


A small bale of barley straw, probably available from a pet shop will clear it; it's what all my neighbours use. BUT the EU in it's infinite wisdom has apparently forbidden it's use for this purpose as it has not been tested. So I would just go ahead and get the barley straw as I hear the barley straw police are having tea at the moment.

Lol Artjak, typical !!

I will get some Barley Straw Extract, thanks both.


I have the same problem, the more water the sunlight can get to then the more algae will grow in your pond. Last year I put water hyacinths on my pond but they went mad and took over, they cut down on the amount of algae but I couldnt see the fish, this year I ve only got 3 plants in my pond, no hyacinth, and the algae has been awful.

The best thing I have found to work is the liquid barley straw, its really expensive but it does the job, once its cleared then I would recommend as others have said, putting a small bale of barley straw into your pond, weight it so it goes onto bottom of pond out of the way and this should help to keep it at bay. Also try and remove as much as you can by hand and let the liquid barley straw kill the rest.

Good luck.




When you say a small bale of barley straw, just how much is that, roughly. The field joining our garden has just had the barley cut, could I just go and get a handful of straw and tie it together. A small bale to me means something about 4ft long. The ones you got before round bales.

Hi lyn,

They are no way that big, there are 3 sizes depending on the size of your pond, the most usual sizes bale 20cmx12cmx13cm, large bale 40cmx18cmx14cm and you can get a xlarge bale, it goes by how many gallons/litres in your pond.

Hope this helps.


Thanks Morph, so could I just go and pick a bunch from the cut barley field, is that the same thing?


The bales my neighbours use are the size approx of a shoe box


I think those little ones are specially produced for pond owners.You can get straw in pellet form too or you can  stuff straw into old tights and chuck them in - just put them on a string so you can pull them back out to dispose of them. ...and make sure the neighbours don't see you in case they think it's a body...

Stephen 7

Lyn...I tried all those remedies, including 'clumping gel', none worked. I went to the garden centre and got a bacterial weed killer that's safe for pets and wildlife. Now my pond looks like the water came straight from a Swiss glacier! All the frogs are happy too! I keep a close eye for any problems but, so far after 6wks nothing has change except the water quality!!!


Would Bacterial weed killer work in my little water feature as its awful at the moment. 

Stephen 7

Hi Angel.   Thats a good question.  Although its designed for small to large ponds I dont see why it wouldnt work. The powder is mixed in in a container with 2Ltrs of water at 40 degrees and and left overnight. The amount of powder used depends on how big the pond is in litre/gallons. So it would take some calculating to work out how much your feature would need...or you could just make a dose for a small pond and use as much as you like, so long as there are no fish or wildlife using it just in case its a bit concentrated for them. 

Personally I would go to the pet shop and ask about aquarium algae cleaner and tell them what its for and see if they suggest anything.

Thank you for your advice Stephen 7. I have tried so many different ways to get rid of the green slime in my water feature. 


A scrub with a brush is the easiest way to clean water features. Bird baths are also prone to a build up of algae  because they're shallow, as well as debris from the birds themselves, and it only takes a few minutes to fix 


Hi Fairygirl, it looks as though I will have to do just that. Thanks for your advice.


Angel  - a little drop of washing up liquid when you scrub as well if you want - then rinse really well, especially if it's a type that wildlife can use. No cost! 

Thanks Fairygirl for your advice.

When is the ideal time to remove barley straw bales from my pond?  It has been in there since, June (now October) and it is a  bit manky!  I always let them float, is that right or should they be sunk?  My first post!  thank you

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