My pond is full of purple slime - please help

[acrossley]

I have a well-established pond in my back garden, but I don't know much about ponds- I moved into the property just over a year ago and since then have just been trying to keep it free from duckweed and putting plenty of oxygenating plants in it.

A couple've months ago the water turned a murky green colour, so I treated it with whatever the chemical is to clear the water. In the last two weeks though the pond has become very murky, and there is a grey/purple coating on all my oxygenators. My hay bale is also covered in this slime, and I can hardly see through the water at all. It doesn't seem to be affecting the fish or the thousands of frogs, but the pond does not look at all well and I can't find anywhere on the net that will tell me what this purple slime is and how to fix it!

I'd really appreciate any help and advice,

Thanks,

Andrea C
Bury, Lancs.

[Kayleigh]

Hi Andrea,

I have never heard of purple slime on a pond maybe its to do with the chemical you put in. Take a sample to a an aquatic centre and tell them what you put in..

I cant help any more but maybe you could pm Dan Salter or dogghound to see if they can help.

[djackso]

I would suggest this is a photosynthetic bacterium (Rhodospirillum rubrum or a Chromatium sp.) that was allowed to predominate when you added chemicals to remove the algae.

I don't think is is toxic.

But I don't think it is not as beneficial for the wildlife as the green algae that you removed.

I'm not sure what the experts think, but I would leave the pond and see what happens. However, I know fish are very sensitive, so I would at the very least start testing the water quality with a commercial kit. I don't know if there is another chemical to add, or what the knock-on effects of this would be.

[m1.carson]

Hi,

Although I sort of agree about leaving it and see, my first gut reaction would be to rapidly change three quarters of the water, although I haven't any qualifications, we've had some bad experiances of bought fixes for problems.

Against other peoples advice, we use straight tap water every time, no additives.

Max.

[Kayleigh]

Originally Posted by m1.carson

Hi,

Although I sort of agree about leaving it and see, my first gut reaction would be to rapidly change three quarters of the water, although I haven't any qualifications, we've had some bad experiances of bought fixes for problems.

Against other peoples advice, we use straight tap water every time, no additives.

Max.

I agree i would do a part water change..

[djackso]

Also, I think you can buy "good bacteria" for the pond. I used a product called sludge buster or something a few times; it's a product which I trust. Not sure if it is suitable for your problem though.

If you go down the route of a partial water change and if it's raining where you are (and you don't have a water butt) try and find a way of collecting as much as you can and use some of this.

I'd never recommend tap water straight from the tap - I'd leave it to sit for a couple of days to allow some of the nasty chemicals to dissipate before using.

As a very last resort, remove just 10 % of the water in your pond and replace with tap water, spayed through a misting or shower attachment into the pond - this should help make the water more suitable, and I'd hope nothing too bad would happen.

But in my area I'd almost guarantee that blanket weed would follow.

If you decide to use water butt water, please use this water as fresh as possible, and make sure there are no "chemicals" getting into this water from a roof used for collection - make sure that the butt is covered with a lid.

Hope some of this helps!

[gudgeon]

I dont know exactly wat the purple stuff is but it sounds like that u have an algi problem. have u tried using an algicid. There are a few treatments that u can use. it might be worth phoning some of your local aquatic centres as some may have testing facilities as some do have around my area.
Is it a natural pond?
do u have a pump and filtration system?
when keeping fish it is always best to treat your pond in spring with a wide range of tretments leaving 1-2 weeks between different treatments.

[gudgeon]

ps You can also get a green water treatment as you did say it started off by looking green

[gudgeon]

pps
there are many treatments for ponds including for using with tap water to make the water safe for wild life. most aquatic centres will be willing to help over the phone or face to face as its good reputation for them.
good luck

[djackso]

Originally Posted by gudgeon

pps
there are many treatments for ponds including for using with tap water to make the water safe for wild life.

Ahh - I never saw these - that's a good idea