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5 messages
28/05/2012 at 23:21

Last summer I put a bucket full of pond weed in my pond thinking it would help to keep the water clearer. This year I've got blanket weed for the first time and think this weed is the culprit as the blanket weed is only around the deep end where the oxygenating weed is. I don't have many plants in the pond, only 2 struggling water lillies, due to vandal koy so thought this would be a beneficial plant that would'nt be of interest to them. It also gets drawn to the pump so daily clearing, but the tiddlers seem to love it so I feel guilty to compost it but I don't think it's earning it's keep, quite the reverse in fact. I'd be interested to hear any views anyone has.

29/05/2012 at 09:03

extra planted will not cause blanket wed this is from either excess light or nutrient how large is the pond?? koi do need a largish area to be successfull and if they are in to smaller expanse of water there could be a build up of ammonia nitrate and nitrite all of which blankety weed will use to grow also what proportion of the pond is in direct sunlight??

30/05/2012 at 20:16

All of it unfortunately and for most of the day, it's quite a large area with 1/3 of the area quite shallow. It's been established for 8 years and up until this winter had about 40 - 50 fish, the heron having visited and left only 4 goldfish and 3 quite big koy, so i would have thought the waste production drastically reduced.  I always get green water but not blanket weed. I even spent £500 on a bigger filter and uv unit which does a great job on the green water so miffed now at the appearance of blanket weed!! Is the oxygenator of any great benefit? it's all wrapped up in the blanket weed at the moment!

30/05/2012 at 20:26

Koi carp are not the easiest of fish to keep in a garden pond - and darned expensive if they provide Mr Heron with a meal or two!

Blanket weed is worse when there is an open surface of pond, so spreading plants are a benefit.  Obviously, waterlilies, but also floating plants like water chestnut.

btw after a number of ways of trying to prevent the heron from taking our fish, we have finally discovered that a grid of floating, open-weave "trellis" (for want of a better description) around the pond margin is the least visually intrusive, and the most effective.  The company that supplies them is called Netfloat (

31/05/2012 at 19:57

I got it,,, I'm not that impressed,,,, It's no defence when the pond freezes over and that's when I loose most fish.  I keep the pump going so that it doesn't completely freeze so that gases can escape, and have seen 3 herons sitting on the ice at the same time, ( a myth that they don't feed together so have dispensed with the services of the hideous plastic heron).  This year I know he has waded in because I noted the oily film floating on the water. So, he either lands right in it, like a harrier jump jet, or he's able to step over the double ring!!

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