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I'm in the process of planning a wildlife pond, hopefully to be built later this year or early next year, it's going to be a very rough crescent shape, aprox 3m x 2m and around 0.8m deep at it's deepest point. I'm using a flexible liner with an underlay, on a sand bed

the advice I'm looking for what's the best type of sand to use ? ie building sand, sharp sand or another type and how deep does the sand need to be ?

thankyou for reading


Gary Hobson

The type of sand doesn't matter at all. The sand simply helps to provide a flat bed so that any no sharp stones don't puncture the liner.

The thickness you need depends on how smooth you can make the bed beneath it. If you have the patience to make a smooth surface, you don't need sand.

Even with sand, it's important to inspect the bed of the pond carefully, and to remove any sharp stones, or hard bumpy nuggets of soil. Soils such as clay may contain a lot of flints, which have sharp edges. It's important to remove them.


Hi John, Ive done a couple of ponds now. I think you'll regret not doing it deeper, once its done thats it. Its a great project I loved my ponds we moved house and have no room for one now. We had a great diving water beetle in ours its the scariest beetle you'll come across, google them


Yup, if I had my time again I would have gone deeper on the digging....anything over a metre is ideal but the deeper the better.  I used old carpet to line the pond before the liner went in but as Gary says, it's mainly to stop sharp stones (and those ever-present bits of blue and white china) puncturing the liner.


Ditto on the depth and I sloped the edges too much on too wide an area to allow for the wildlife getting out but not the depth for plants



Agree with deeper in one section of the bottom at least. I've found about a metre is fine. Like Boticelliwoman I used carpet - actually mostly underlay - as well as sand.

Thanks for the replies

I can go deeper, but I was a little worried about the sides of the pond being too steep. The area for the where the pond is going in, is aprox 5m x 3.5m, so I don't really want to make the pond any bigger, the area around the pond will also be an extention to my wildflower garden.

I'm not sure what my soil is like, at a metre deep, nearer the surface it's quite good soil. But around where I live there's a lot of clay type soil as you go deeper.

Sorry another question but is there a maximum angle for the sides of the pond ? without having to build any type of a retaining wall

thanks again



it doesnt need to be same depth all over i did over a metre just to one side and a metre on other. mark out the shape you want with your garden hose dig down to the depth you want and when youve done that back breaking bit(I was lucky our neighbour had a jcb and felt sorry for us werent we lucky it reached into our garden) Then you do a shelf within your shape for sitting baskets of water plants about 25cm down, make sure its wide enough(and flat enough) to hold your baskets or they may tip into the pond! this shelf only has to be to one side just decide on yor planting and of course this shelf is also for wildlife to get in and out of the pond I softened my edge with stones of all sizes this also helped wildlife. I used boulders to soften the edge of the pond. Another tip is to use a long spirit level put a plank of wood across the finished levels before you put down your liner, if its not level you'll see the liner which is unsightly and it will get sun damage.Do it again when the liner is in you can always pad up an area with sand to get levels right. It is so important to prepare the pond carefully as it can look awful if not right . Good luck Im so jealous

Thanks again for the advice

I'm hopefully going to get it started this autunm, which gives me time to get my plans right and to save some pennies. I'm affraid mine will have to be all dug by hand, the only access to the garden is via some steps so a mini digger is out of the question.

thanks, no doubt I'll be after some more advice before I've finished



looks like you'll have a few raised beds about too..Thats alot of soil to dig out happy digging. Why dont you have a digging party it might be worth a bbq and a few botttles of wine


You can just stick with your first plan and then dig a deeper hole somewhere in the middle or at one end.  The point of the depth is so that over-wintering amphibians have a safe place in the mud that won't get frozen.  However, you do need to make sure that there's no rotting vegetation in the pond as this seems to cause a build up of toxins if the pond is frozen over for any length of time.  When we had the bad winter a couple of years ago, hundreds of frogs died in garden ponds and research showed that:
a) a hole should be kept open in the ice at all times
b) any snow laying on top of the ice should be cleared as the lack of light prevents plants oxygenating the water
c) ponds should be cleared of as much dead organic material as possible before winter


I think we need a summer before we can have bbq or digging party. A lot of the backfill will be used to landscape and level the area, I'll try and post a picture ( when it stops raining ) to give you an idea of what the area looks like

If I'm thinking of the same winter, we were snowed in for three days, which doesn't sound too bad, but we live in a fairly large city. I've read somewhere one way to keep a hole in the ice is to boil a pan of water and use the pan to melt a hole in the ice

That pond and garden looks great I hope that I can manage to create garden like that one day, but at the moment I think it's a bit beyond my skill level. It's interesting to see the different stages of the pond construction



Some of us can only get 'stupidly tiny' ponds in their gardens.  Besides, it wasn't the size of the pond that caused the deaths of so many frogs two years ago, but a combination of factors.  My pond is just under a metre deep, about a metre and a half wide and 3m long, it didn't freeze solid but all the frogs died.  My friend has a pond 4m square and almost 2m deep and he lost all his frogs too.
I go out with a pan of hot water now when the pond freezes, as much for the birds and other mammals as for the frogs and I also use an old pop bottle with gravel in that bobs about in the water and helps stop the ice forming.


Finally managed to gain control of the tv and catch up on recorded shows, I watched gardeners world and with interest the part with Kate's wildlife garden. I always thought that a water pump was a massive no no, but it showed a small stream running into the pond, is there some type of wildlife friendly water pump?

Also with what cufcskim posted is there a minimum size for a pond?



Really you can have a pond of any size you want.  Some people can only have tiny ponds in their gardens but the biggest you can fit in the better.  Normally wildlife ponds don't have pumps but if you want to create a stream effect like wildlife kate then you have to have one (unless you're lucky enough to have a natural stream running through the garden).  I use a small floating solar fountain to help keep the algae and duckweed down and I believe you can get solar pumps but I'm not sure how effective they are.

Gary Hobson

You'be mentioned that there might be clay as you go down. You ought to know whether your garden is on clay. This is an important point.

Clay is hard to excavate. You might start out with good intentions of making a deep pond, and then, when you start trying to exacavate the clay, you may well revise your plans, and decide to make the pond a lot shallower than you'd intended.

You can't actually dig clay. If the weather is dry, then clay is like concrete. So it's a job for a pick. If the weather is damp, then clay will be sticky and heavy. It's difficult to stand on wet clay, as wellington boots stick to it. And if it starts raining, the water will not drain away. So you'll have a pond to stand in while you try to work.

Also you said you might use the excavated material to landscape the area. If the material is clay, then you won't be able to grow anything on it. In my garden the topsoil is about 9 inches deep; that much is usable for landscaping, but anything deeper is not. You could dig a small test hole in advance and find out what you've got.

You need to hope that you won't encounter these issues, or that they won't turn out be too much of a problem.

I'll dig a trial hole when I get chance and let you know what I've found. If it is clay I'll have to get some top soil to cover any landscaping I do. If I do go for a pump, I'm not too sure a solar pump will be strong enough especially in the winter time with the longer nights. I'm sure I'll be able to find a low power pump to run a small stream. I've already been told the pond can't take over the garden, so I think I'll be sticking to my original 3 x 2 size, well maybe an extra 0.5m here or there won't make too much a difference


Good luck, whatever you end up with! My pond is my favourite spot in the garden, apart from having plants there that won't grow anywhere else, I'm just like a kid when it comes to peering into the depths to watch tadpoles and beetles.  I love seeing the little frog heads popping up amongst the duck weed, watching the birds bathing, bees drinking and damsel and dragonflies flitting about; you're going to get hours of enjoyment!!!!


I have a natural pond 4 feet in depth x 25 feet in diameter. There is no liner, just clay. My question is: can I successfully use a water pump to pump to a height of 3 feet above water line to create oxygen, as well as, using x 2 large air stones and the rest is nature, i.e. lily's, marginals, oxygenating weed etc.

Thank you in advance