Ok here we go again for the 3rd year running my pond is crystal clear all winter when it's to cold to sit out and look at it and as soon as the sun comes out the pond goes cloudy
My pond is 10x8ft x4.5ft deep it has an oase aquamax 16000 pump with a 6" skimmer attached going into an oase filtoclear 30000 there's a brand new uv bulb been put in at the start of may also there's one of those oxytex air bubble things as well just for good measure
There are probably about 20-30 fish in there ranging from 3" koi gold fish etc to a 2ft long sturgeon they get fed once a day in the morning and also gets hoovered once or twice a month my local dealer suggested doing it every week !i have various plants in there also
When I run a net over the bottom of the pond I'm able to scoop up a net full of sludge all the plants etc look as though they have a layer of silt on them to I've even got an electronic weed controller to see if that would help
So the question is why can't I keep the water clear in the summer or what am I doing wrong as this time next year if I can't get it clear its going to be a sand pit

Without seeing it in person, I can only offer suggestions.

If it only happens in summer it has to be something to do with the fish, since that will be when you feed them?

What goes in one end must come out somewhere else.........

Why don't you fit that bottom drain you mentioned? Unless you get a lot of floating debris you may want to "unplumb" the surface skimmer.

Cloudy green, white, brown??? Its really hard to suggest anything without more detail but I would guess its either water quality or algae related.

Don't lose patience, its not actually anything in particular that you are doing. its likely to be jut a bacterial bloom. As the water warms up and there's more light available, nutrients will increase in the pond and this will encourage bacteria, algae and animal life in the pond. It's showing something is out if balance, but the cloudy water won't bother the fish. I think most people with ponds go through a phase of having to put a bit more work into maintenance this around this time of year. There are a lot of fish in there, and that wont help matters. the sturgeon is not a sensible inhabitant though, you have a reasonable sized pond but that's not big enough for a sturgeon, even if its a sterlet, I wouldn't recommend housing one in a garden pond. Koi should reach about three feet in length at full size... So I would actually recommend rehoming them. Keeping it just to goldfish will give you larger, happier goldfish. Remember they will reach about 12" long. Don't drive yourself crazy by trying to get things perfect, you could end up making things worse by trying to work against nature. I would also recommend cleaning the bottom of the pond a little more often, but do it in sections, you don't want it to be too clean, you need the bacteria and insect life that will be present in a mature pond, but you don't want to allow too much gunk to build up and be rotting away at the bottom either. I would try reducing the amount of food you are adding for now until pond starts to clear up, the fish will not starve, they will find other things to eat in the pond anyway. :)

I've just cleaned out the filter again in pond water of coarse and I've removed the skimmer so all the water is coming from the pump direct into the filter and I'll keep my eyes open for a bottom drain fingers crossed it gets better

Hi i have just gone through the exact same thing ... i have now got a 'polisher' which is basically a filter full of purely fine filtration media 2 foam pads and 2 wool fleece layers. I have also just replaced my sponges/foam filters in my main filter i thought it was just the aquatic place trying to sell me something but true to his word the sponges had shrunk!!!

i added the 'polisher' the day before replacing the sponges in my other one so im not entirely sure which worked most but after 24hrs running my water is crystal clear and all 6 level that i test my pond for are perfect.

the polisher was purely home mad ( i bought sheets of fine filter foam and fleece and cut to the size i needed)it cost £30 in total!!!


hope this helps

Just a quick update on the water situation, while on holiday last week we nipped into world of water in Bicester and was discussing my water problem everything he suggested I had already tried so no joy there but he did suggest that my pond was under filtered and recommended a new oase screenomatic filter but even with a bit off £900 still had me in shock especially since I hadn't long paid £400 for my oase filtoclear 30000 so I tried the cheaper option of replacing the original 13 sponges with 9 new ones and hey presto less than 24 hours later a crystal clear pond again.
I,ll just have to see how long it lasts now

4 days that's how long my clear pond lasted I'll clean out the sponges tonight im hoping that they may just be chocked from having to initially clean the pond when the water was really green but we'll see or not as the case maybe