I don't know how accessible the pond is, but I would suspect young hoodlums with soap. Possibly, if there has been a windstorm, or a lot of runoff entering the pond, there may be too much organic debris in the pond, but that filter should reduce the frothing effect from that. You might want to check that the bulb hasn't burned out.

Well thanks for your swift reply Tugbrethil. Your first suspicion about sabotage is not the case as we keep the gate locked and they would have to scale our 12ft privet hedge which is a very tough proposition. lol John has taken the filter to pieces and given it ia thorough clean and checked the bulb which is working ok. We are just at a loss not knowing what is happening. We have been pond people for many years so used to the usual things occuring. It just looks awful as it is filling the whole space of the pond. The fish seem ok and as we have had the problem for a couple of weeks it dosen't seem to be harming them. A mystery I hope we can soon solve!

The only other thing I can think of to do is to put a nylon stocking full of activated charcoal in there for a while.

Have you topped it up with rainwater Sue ?
I noticed that after heavy rain our water butts have froth on top.Also the water has a brown tinge to it. I just assumed it was dust from the volcanic eruption,or it could possibly be a local pollutant as we live in the same area of the UK.

Volcanic ash would produce mud, but not froth (unlike wood ash).

Hi Aster rain water does fall in naturally of course and we have in the past during dry periods put some in from the water buts but this seems so different. Yes it is brown the same as in the saved water so could I suppose be something to do with the volcanic ash! I have Googled and found it could be organic, possibly from plant material decomposing in the pond. The sight suggested that it is a quite NORMAL thing and will sort itself out if we have patience. Something we will have to watch and wait for. We are just so pleased that the water under the foam looks clear and as the fish seem happy we will just have to wait and see.

Thanks Tugbrethil anything is worth a try.

As you say,the fish are happy and not showing distress which is the main thing :)

Grannysue i think Aster has hit this problem on the head as i recently called on a lady to sort out a damp problem and also noticed a great heap of foam emerging from a rainwater pipe where the only water from the pipe was off the tiled roof, Hope you get it sorted.

Yes Aster I would be upset if they were ill as we have reared them for years and they have grown so big. ;~))))))

always like dogs or plants or infact humans check there general health and if they are ok you can rule out a problem as such . washing up liquid is leathel to fish so there is know chance of that . the thing about u.v filters is the bulb will keep running but light comes in more than one spectrum and some get week in a bulb so dont do there job anymore . this happens aprox every full year on . you wont notice bye eye as the bulb looks know different . light actualy or the right spectrums anyway that help plants has real trouble moving through water . you dont very often see deep fish tanks with plants in without realy expensive lighting . id say its a good sign in your pond for health but at least definatly a natural thing . if you go down the river near a stanch you sometimes get this froth . i believe it comes from duckweed but im not sure . try changing your bulb if its been on for over a year granny sue .

Thanks Corgiman for your info. It is beginning to look a lot like it might be connected to the rain water and you have identified it in your working life so perhaps it will clear on it's own.

Noseypotter thankyou for your input which has given John and I something else to concider which does make a lot of sense as we have had the same bulb for some years now. We have just taken it for granted sadly that it is still performing it's job. We are going to change the bulb and hopefully it will either solve the problem or at the very least make a big difference.

Everyone who has contributed with advise: I can't tell you all how very gratefull John and I are for all your wonderful help so a big thankyou! :} ))))))

I know that the uv light we have in our fly zapper in the kitchen should be changed even if it is still working.We have had it for a few years but only use it 4 months of the year.They must be similar bulbs and loose their effectiveness.
I hope this solves your problem Sue :)

realy you havnt got a problem but if the bubbly water bothers you it could well solve it . i have some blogs on here of my garden on here and some short films on utube under the search word noseypotter . i have a raised pond about 26" deep and about 2000 gallons . ive built the waterfall over the pond if you like with a pagoda with bamboo screening over that . i dont have to use uv bulbs as not enough light hits the water and i have a living filter of charcoal and watercress . i swear the pond is clear as a bell and the fish are very well including a 30" sterlet . the downside is in my pond i cant keep lillies or other pond plants .

We are in the process of getting the bulb and searching shed for charcoal to try that. Many thanks again for your your ongoing help Aster and Noseypotter. Sorry to be so delayed in answering. Best wishes Sue x

ow dont worry granny xx .

We have been and bought our new bulb and John has installed it so now fingers crossed...lol

the thing is if your fish are ok you didnt have to much to worry about healthwise but hopefully it will get rid of the bubbles .

New bulb has been in since Sunday but foam still coming. We are trying the charcoal now so maybe that will help. As we are going on holiday on Sunday I won't be in touch for a while and will miss you all. Love Sue x

dont worry sue if the fish seam ok eating etc then they probably are . see ya soon hopefully xx .