Why are my pond plants and animals dying?

[djackso]

No, I think the algal toxins are fairly specific to higher organisms, but there could be several things going wrong in the pond at once - a picture would help, possibly?

All the best,

Dave

[BREnvSciGang]

So...

Where is the best place to get the water for a new pond? Will clay soil generally be enougth to trap water or is a liner required?

[Jez]

I think that's a matter of how much clay content is in your soil to how well it will trap water

[Tursiops2]

Originally Posted by BREnvSciGang

So...

Where is the best place to get the water for a new pond? Will clay soil generally be enougth to trap water or is a liner required?

Unless your soil has a very high clay content, and you are prepared to put the effort into "puddling" it (trampling it with bare feet to compact it and make it impermeable) then a liner is your best bet.

The best water is rainwater - set up some water butts to collect water from nearby roofs. Tap water can be used, but it is high in nutrients which tend to cause algal blooms, turning the water green and murky. Unsightly, but not usually a problem in the long term.
T2

[steve_nova]

And then as noted above, get a bucket of sludge from the bottom of a healthy pond and put this into yours.

Steve.

[BREnvSciGang]

Okay! Thanks! I think we are going to use a liner (althougth I don't like the idea). We have contacted another conservation place who also built a pond for the greaty crested newts and they used a liner. We do currently (they will be demolished eventually) have a few huts (crude outside classrooms) near the conservation area. We could probably hook up water butts to the guttering but I would worry about vandalism by students. I also wouldn't want to experience the same problems as the thread starter in terms of using poluted/stagnant water. It is interesting that simply trampling th soil should make it impermable. The people who will dig the pond are local volunteers - they may not mind doing the trampling. At least then it will fill with rain water directly. I am not aware of the clay content in the soil, but I know that we have problems with subsidence in the past as a result of clay content. To install a water tank, a great hoel has been dug and the sides have a very clay colour.