Natural pond

[The Flying Tench]

I've got a small natural pond about 3 feet deep withhalf a dozen goldfish in it. And I know nothing about it. I found one of the fish on the top dead today, and am concerned if the others might be at risk.

 

There's a small weed (algae?) all over the top. It's like a 3-leaf clover, but a bit smaller and with no roots. Would this be harmful, maybe stopping the surface absorbing oxygen? There's plenty of other weed, and the water is fairly murky so, with the weed, I don't always see any fish!

 

Obviously the warm weather can't help. Is there any simple way of increasing the oxygen in the water without electricity (pumps etc)?

 

Thanks

[Alan Hammond]

The fish death could be from any one of a dozen causes including plain old age. At three feet deep your pond should not suffer to much from the sun. Just keep an eye on the pond for any more deaths or signs of fish looking distressed.

 

The plant on the surface is known by various names but commonly Canadian pond weed. It is a thorough going damn nuisance and virtualy imposible to get rid of. I know I have it in my own pond courtesy of a local garden centre who sold it as Fairy moss. I would advise netting as much out as you can once a week or so. It will grow back but in doing so it will take a lot of nitrate and other chemicals out of the water.

 

Other than plants the only way that I can think of to oxygenate the water without an outside electricity supply is by putting in one of the solar powered fountains that are advertised in the papers now and again. I am afraid that I have no idea how effective they are as I have never seen one in use.

[fisherman]

Alan, are you sure it is Canadian Pond weed, it sounds more like Duck weed to me. I thought the Canadian stuff was long with small leaves as is sold as an oxygenating plant. It can get a bit vigorous mind and a tight eye kept on it.

 

FT try to cover at least half the surface of the pond with water lilies to help keep the water clear.

Dave

[jevs]

Alan, are you sure it is Canadian Pond weed, it sounds more like Duck weed to me. I thought the Canadian stuff was long with small leaves as is sold as an oxygenating plant. It can get a bit vigorous mind and a tight eye kept on it.

 

FT try to cover at least half the surface of the pond with water lilies to help keep the water clear.

Dave

 

Must admit that i thought it was duckweed.

 

The above advice is good.....get a small lilly in there

[Alan Hammond]

I think that there is a whole lot of confusion between Duckweed and Canadian pond weed. Quite frankly I do not know the difference between the two. When I was up at the garden centre a couple of weeks ago the lad there, who claimed to have a pond of his own with the same stuff in it, called it Canadian pond weed. But I have also heard it called Duck weed as well, among the politer names used for it.

 

Oddly I have a similar though slightly smaller plant in my aquarium and take out two to three four inch net fulls every week and I am running that tank over filtered and over oxgenated at thirty degrees celsius. I tolerate it in the aquarium because the hassle of taking it out during the weekly water change is far outweighed in my opinion by the good that it does at getting rid of nitrates etc.

[fisherman]

There is another small floating plant called Azolla, sometimes I think sold as fairy moss. This goes an orangey sort of colour in the Autumn and is not hardy except in some sheltered spots. Looks like small crinkles up the leaves and small hairs that keep it afloat I think. Might it be that in your tank.

Dave

[chesters1]

if its duckweed (and your description looks like it) get rid of it it has no place in a pond ,its extrememely difficult as its so small but a kids net should be ok .

i like the word "natural" (titters behind hand)

[fisherman]

This one shows Canadian Pondweed

 

http://www.microscopy-uk.org.uk/mag/artnov00/dwelodea.html

 

This one is Duckweed.

 

http://www.arkive.org/species/ARK/plants_a...ae/Lemna_minor/

 

Dave

[The Flying Tench]

Thanks everyone. Well, I've got both! I bought the Canadian pondweed in the shop, and it's filled up the pond - though it's not too difficult to pull out.

 

And the Duckweed just appeared. The main difficulty with netting it is the Canadian stuff which makes it hard to pull the net across - but I can pull that out.

 

I don't quite understand the point of the lilies. is it simply that if you cover the surface with lilies it can't be covered with Duckweed? But I'd rather have some of the surface that wasn't covered with anything!

[chesters1]

lillies are managable ,they come in varying sizes suited for the pond ,duck weed doesent respect sizes and will cover it completely .

some hoorendus plants (including canadian pondweed) are put in ponds at first there ok but swiftly get out of control.

a slight difference to normal pond plant life could be water chestnut ,nice shade plants that float about (can be resticted using a wire just under the surface to a specific part of the pond) fine in warm sunny ponds and have the advantage they die in the winter and hense cant get out of control.

not being incharge of a ornamental pond anymore but the ones we used when i did looked pretty fine but the pond being 50ft across (circular) had problems with the breeze rounding them up into one spot ,did fine in a sheltered but sunny one though.they can be a problem in really sheltered ponds but generally our winter kills the blighters off ,i read somewhere they are a problem in parts of N america where they have got out of control! natures way of paying back for that dammed canadian pondweed over here

Edited July 10, 2006 by chesters1