Green Water In Garden Pond

[imd123]

Also posting under Animals by the way!

Our well established 1500 gallon garden pond has always suffered from having green water. I have tried barley straw and a UV light and have plenty of plant cover and am certain the pond is not overstocked. On some sunny clear days the water does clear but doesn't last.

Any idea what may clear it please? Thanks to anyone who replies.

[thundercrack]

hi, too much open light. I have bought these miracle cures that kill the green colour, but they turn the the water dark brownish. I have a water feature pond that is totally clear because there is a trellis work in chinese pattern behind and above that is occluding the direct sunlight. the sun still reaches the water so the fish can sunbathe(or whatever you would call it) but it's not long enough to feed the algae that breed in sunlight conditions. I think you will find that there is no other answer. build a shade of some sort, give the pond only a couple of hours of direct sunlight a day.
alf.

[imd123]

Thanks Thundercrack. I may have to consider that. I have the pond surface well covered with plants which I would have thought would have been good enough though!