Help! Green froth attack

[Sequoyah]

Hi, i'm new to this forum. I've had a pond since I moved into my house nearly 16 years ago and never had any major issues with it. I have never stocked the pond, the fish have naturally multiplied and I probably have too many now.

In the last few days the pond has developed a bright green froth/foam on top of the water. It smells quite acrid, like seaweed/tide plants when the tide is out.

I have changed my UV bulb to see if that helps, but anyone any idea what has caused it and what I can do to get rid of it?

I haven't changed any of my habits, still feed the fish at the same time, same quantity. The only thing that's different is that I was experiencing a slow down in the water flow from the filter so took it apart and unblocked it. The water flow is not much better, but I can no longer see the fish!

Any guidance would be appreciated.


Thanks

 

[Dave 54]

Looks like your pond has developed a form of algae called Blanket weed the best way to rid the pond of it woud be Cloverleaf Blanket answer however a word of warning you use it at your own risk always add extra airstones via a large koi airpump to the pond when using this product
What filtration do you have on your pond and how often do you do 40% water changes or clean the ponds bottom with a pond vac
[unless you have a bottom drain that is] ?.

Dave

 

[Sequoyah]

Hi Dave, thanks for your response, it difficult to tell from the photo but I don't think it's blanket weed (which i've suffered from in the past), this is a film/froth that sits on top of the water, it smells very stongly of green plant matter, quite an acrid smell. I have an Oase filter which sits outside the pond and has a new UV bulb. In the pond is a decent Oase pump. I've had this system for maybe 6 years and it works well. I also have an aerator that is happily bubbling away. I changed the stones about a month ago as the old ones were getting clogged up. I changed the water (about 40%) a few days ago to try and bring this under control, I treated the tap water as it went in to make it safe. I guess i'll keep an eye on it and see if it get's any better in the coming days.