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blanket weed

denise butcherdenise butcher Posts: 133
in Talkback

we have a large koi pond with healthy koi, but masses of blanket weed...where has it come from never had it before this year and how do we get rid of it without hurting our fish?

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Posts

  • Blue OnionBlue Onion Posts: 2,995

    Twirl it around a cane and put it on the shore so creepy crawlies can get out and back into the water.. then toss it on your compost heap.  

    Utah, USA.
  • WelshonionWelshonion Posts: 3,114
    Try and get hold of some barley straw and stuff it in some old tights with a stone to sink it. Chuck it in the pond.
  • denise butcherdenise butcher Posts: 133

    Thanks I have done both suggestions x Oh and someone has told me to throw in a bunch of water cress????

  • WelshonionWelshonion Posts: 3,114
    Blanket weed will be the least of your problems if you put in watercress!
  • Mark 499Mark 499 Posts: 380

    If the pond is very large you will probably need the entire bale of straw, it's not a cure it's a preventative measure you will still need to remove the blanket weed by hand.

    Also as it breaks down it reduces oxygen levels so do not use it in hot weather, it may well take a year to work.

  • LynLyn Posts: 23,190

    Mark, would the barley straw liquid be any better?

    Gardening on the wild, windy west side of Dartmoor. 

  • bekkie hughesbekkie hughes Posts: 5,294
    Not sure if this is any help, i only have a small pond, so it heats up quickly and encourages blanket weed, the only thing that got rid of it was when the surface is covered with duck weed, i assume this stops the sunlight getting in and uses up nutrients in the water so blanket weed cant survive.



    I imagine you dont want to infest your pond with duck weed, but maybe something else which will cover more of the surface would help, maybe water lillies? Not sure what you can have with koi image
  • Mark 499Mark 499 Posts: 380

    Lyn, some of the barley straw liquids seem to work & some have no effect whatsoever , blanket weed grows where there is an excess of Nitrogen & Phosphate in the water so what you really need is something to reduce these such as Viresco Koi

  • treehugger80treehugger80 Posts: 1,923

    blanket weed grows by using nutrients in the water, the koi are producing the nutrients (i.e. fish poo) as they get bigger they produce more poo - it could be why its only just started being a problem.

    You can use barley straw, a UV filter addition, chemicals (not recommended) or shade part of the pond either with natural plants (water lily's) or with shade cloth in summer. or a combination.

    I use barley straw, water lily's covering nearly half the surface and a UV filter. one of my friends has a filter system that runs thru a bed of watercress and then water reeds to take the excess nutrients out. works really well!

  • Mark 499Mark 499 Posts: 380

    The UV will not work on blanket weed though, it only works on clearing the algae that cause green water.

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