Anyone know any tricks for curing "green water" in a pond?

The pond is about 4m x 2.5m and varying depth. It was used to keep koi by the previous owner of the house. When they moved they took their koi %26amp; filtration kit with them (fair enough) and left some goldfish.





I fitted a pump and filter system matched to the volume of the pond but slowly the water has got greener and greener. (The goldfish are thriving and multiplying however!) There are plenty of plants - 4 lilies, 6 water-hawthorn, plus some others I don't know the name of (wife is the plant person). There are plenty of snails and even 6 large swan mussels in there





I've tried barley bales. I've tried chemicals. I've tried emptying 1/2 the water... I'm fed up with having a pond full of pea soup!





Anyone got anyone suggestions?

Anyone know any tricks for curing "green water" in a pond?
hi, you have to change the bulb in your UV filter at least every six months for it to be effective as it loses it's strength, another thing might be that the UV unit isn't big enough for your pond, you always need a bigger size if your pond is in full sunlight. Also have you got a very powerfull pump, it might be that you are running the water through your UV too quickly and you might just need to turn your pump down.





I would check those three things as most of time its one of those reasons. Barley straw is okay but it takes a long while to work, don't empty your water, putting new water in will create an algae bloom and make the problem a lot worse. The only way to stop green water (apart from a UV) is to cover at least 3/4 of your pond with floating plants.





Your pond will clear after you sort out your UV, but it'll take two or three weeks.
Reply:i think this is because of plangtons, plangtons will devolop when the water has enough food (manure) to grow plangton. i believe there is some plangton removers available in the market, especially with the garden people who making lotus-lilly ponds. please try to contact them . another thing is the direct sunlight, it will also will cause the plangton growth. did you know some varieties of carp fishes are eating plangtons. that might be the reason for the pond, that is why when you were came the water was plain. idont think a normal filter can clean the entire pond in an open atmosphere. you can priffer a more powerful one.
Reply:a bale of straw is the best thing you can buy its cheap and works within a few days I have a big pond and had the same problem and this cleared it after going to different shops and trying different products that didnt work.





Hope this help you.
Reply:stop the cats peeing in it
Reply:if got straw in a net in the bottom of my pond and i have goldfish in it it will keep your pond clean but not very well,i think when you feed your fish they wont eat it oll and try to get the food out or it will just make it more green especially when it summer and its hot
Reply:Algie has formed because of sunlight %26amp; not enough water movement;see any green in fast moving water?? two solutions too try IMO Bernard
Reply:As the previous post says, and we did use with goldfish.
Reply:I have had success with a bale of straw, never tried barley. I have a 3/4 acre pond and use aqua shade. I have perch, bass and blue gill. I don't know if you could use it with gold fish. Good luck, I hate the green stuff to.

Park Hotel Ahrensburg