If it is clear in the shallows the water may still be as clear in the deeper water, but the silt on the bottom could be one reason it looks murkier in the deeper water. Maybe some plant debris could be pulled out. Other reasons could just be the actual time of year as my pond also has days when it looks pretty murky and I cannot see the bottom at all in the deep parts. It may be just a wait and see if it clears over the next few weeks as you do say that the set up looks fine. Yesterday in the sunlight mine was clearer than it had been for a while. Sorry this isn't really much help but also try to remember how your other ponds were as you say you are not new to ponding, did they get like this at all? At the moment the frogs are back for mating and they do murk up the water so could that be another cause.
What a lovely size pond you have though. Mine is about 17ft by 12ft. Pics can be found at the link below.
Hope you get it sorted.
Alison

Here is a link that might be useful: Alisons pond and garden

thanks for that have just been looking at yours..looks great alot of work gone into it ! will have to get some pics of mine tomorrow and see if i can put them up.

The pond has a green genie 48000 with 3 outlets around the pond and has 11!! airstones with 2 in the actual filter,,,(is this normal?)

I am just wondering if you are in touch at all with the previous owners of your pond (by having a forwarding address or something.) You would think that they would have left details of the pumps and filters etc. 11 airstones does seem a lot, but I have no idea if it is a lot for the size of your pond. I haven't any in mine. I have two pumps, one feeding the waterfall and the other into the filterbox. Maybe you can post the question again on my site as there are some knowledgeable people there.
Alison

Lucky you having such an enormous pond!

Barley straw helps keep my pond clear. It's only 9' x 8' but I don't have a filter or pump. At this time of year it does get a bit murky, but then clears itself.

I remember seeing an enormous pond being built on a gardening programme (Gardeners' World, I think) and they threw in bails of barley straw. I use mesh bags that veg come in but mine don't need to be too big. I add new ones every three months and replace the originals after six months. I've got a system for dating my bags so that I can keep a check on the dates.

I was at a pet shop getting barley straw recently and the girl recommended using old tights full of straw. Weigh them down so they sink or the neighbours might call 999 thinking there's a body in the pond!!
Big Kid

Hi-

Hope you enjoy your new pond, it sounds like it is quite established. I would suggest watching it over the next year, so you can find out what flora and fauna are in it and it's own pattern. Murky water especially at this time of year does mean that something is thriving in there--so your amphibians could be turning up the mud. And of course their offspring will need to eat too and green water has all the nutrients they need.

I have a decent size pond and no filters. But there is a pattern to the clarity of the water depending upon the time of year (around June/July it goes very clear for awhile, then murky again and later clears when the weather goes cold.) It has never been so murky (except early in the first year before the plants were established) that it was unnattractive. Snails seem to clean up the pebbles in the beach and the birds come down to eat the snails. Really like watching grey wagtails coming down looking for snails.

Also, you might have oxygenators that help keep the water clear, and you might not. So see what comes up. If you put in new plants that will also make the water green for while too. If you put chemicals in, you really won't know if that is mucking up your eco-system. So other than some barleystraw (organic if you don't buy the expensive pond-versions) I would just watch it and see what you discover.

If it doesn't have large fish in it, and you want to put some in, I would also suggest waiting and seeing what your pond has. Who knows, you may have a thriving crested newt population and you don't know it yet! Similarly frogs and toads needs all the help they can get these days so a few ponds free of hungry fish can be important.

Have to admit too, I don't get blanket weed anymore but I do kind of miss it---it was always a great excuse to get 'hands on' in the pond and see what was it. Great for the compost heap too.

Have fun!!

Chip

thanks everyone thata all a great help i have now found out which pump it is green genie 48000.
Pond has about 10 18" koi 6 grass carp12" and a selection of goldfish loads of frogs one toad and too many newts to count !!! its amazing!

Have posted some other questions on the other site..still trying to post a few pics though!!

cheers jon