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pond dilemma

Dear all,

I'm new to this forum. I was finally allowed (  ;) )to make my first wildlife pond. But now I have some doubts about the design. I have read many sites and folders, mainly from all the different wildlife conservation societies you have. Basically, 20-30 cm of water should be sufficient for a wildlife pond, while the older adage is to make it at least 80-90 cm deep in order it not to freeze. I believe this is quite obsolete, at least were I live.
I was afraid that 1) the water would warm up too much, and I'd lose too much by evaporation because of the lack of volume, 2) it wouldn't offer sufficient possibilities for hibernation, 3) the volume wouldn't be enough to reach a biological equilibrium.

I've made a frame (roughly 8 m², 3 x 3.3 m at most but with some 'cut corner', so it's not square) and dug out shelves of 10 cm depth and ± 25 cm wide. The idea was to have it sloping until 15 cm deep, and then have a shelf 25 cm wide at this depth. Basically because I thought that 10 cm at the edges would already be quite deep, and to save some pebbles. Now I'm doubting to level them at 15 cm, and have 50 cm wide shelves, so that marginal plants would have sufficient space to root, and to slightly increase the water volume.
Next I have 20-70 cm wide shelves at 25-30 cm depth, which I thought needed to be the majority of the surface since most animals would be at this depth and also taking into consideration evaporation. I have - at least for now - most plants in baskets 9-13 cm high, and it appears that this is too shallow, with many oxygenators hardly being covered by water (although I need to say that the top 10 cm is not yet filled, but taking int account that they still need to start growing ...).

Next I wanted to have a square meter of 65 cm depth to create a bulk of colder water, but while digging I adjusted this to include a 45 cm shelve 20 cm wide on three sides, ending up with about 50 x 80 cm at 65 cm deep.

The result:

So now I'm doubting if I should increase the deeper parts, i.e. digging the 45 cm down to 65, and sacrificing some of the 25-30 cm shelves to create 45 cm shelves. I would mainly do this to have more temperature and volume buffer, and have more space to put my oxygenators/deepwater plants, which would probably benefit from a deeper location?
I now have:

* shining pondweed (Potamogeton lucens)
* curled pondweed (P. crispus)
* water crowfoot (Ranunculus aquatilis)
* amphibious bistort (Persicaria amphibia)
* erect (?) water milfoil (Myriophyllum crispata, which was a mistake, I wanted spiked water-milfoil M. spicatum, but it's not available)
* mare's tail (Hippuris vulgaris)

I have put lava and pond substrate in the deepest part.
In 2 corners I have dug out some squares up to 40 cm to put yellow flag to additionally help filter the water. All plants (oxygenators and yellow flag) are planted in substrate, with as much of the planting/container soil removed.

There's of course also a soft sloping beach (although plenty of edge to crawl out). There's a small bog next to it with the pond draining into it when it's full.
Most edges would have pebbles.

Next to the depth issues, I have following concern/question. I've filled it last week, with the very sunny and hot weather. There's 2 kinds of hornwort (Ceratophyllum demersum and C. submersum) floating, but not the quantity I would have wanted. I have floating pondweed (P. natans), water soldier (Stratiotes aloides) and frogbit (Hydrocharis morsus-ranae), but also not a lot. With last days hot weather, the water has turned quite greenish. It's filtered (carbon filter) rainwater, and by no means I want it to be sterile. I guess there's no avoiding this until the oxygenators are starting to take off and the pond is getting established? I know I need shade/cover, and I hope my plants will grow, but now the frogbit is turning yellow, which I suspect to be from the intense sunlight? I don't know about the nutrient status of the pond.

So, should I bother making the shelves deeper? (with justified argumentation :) )
The green water is normal at the start, or have I not put enough hornwort and floating plants?
Should I worry about the frogbit?
Also, I have quite some folds because of the different 'pits' and corners. How can I minimize capillary forces? I was thinking of folding back the edges towards the water.

Thanks for any advice.


  • furorfuror Posts: 5

  • tuikowhai34tuikowhai34 Béziers, Herault, FrancePosts: 701
    @furor Hello and welcome to the forum.  That's a pretty flash pond you have there.  Puts mine to shame.   But what the heck as long as the wildlife can enjoy it!!!
    A good hoeing is worth two waterings.

  • furorfuror Posts: 5
    Thanks. Far from finished, though!
  • FairygirlFairygirl west central ScotlandPosts: 35,358
    You're overthinking it.  :)
    No pond is perfect. Relax and enjoy it for a while. You can add or take away bits you like/dislike. SOme plants will thrive - others won't. Same as in the garden.
    Ponds heat up when temps rise, and cool down when the temps do likewise. You can use something to float on the surface to help with freezing - I use a piece of plastic coated piece of polystyrene, which has an indent on the base, and it's hooked over a branch at the side. Water lilies and other surface plants will help with shading the surface in the summer. I've had ponds of every depth - from b*gger all to about 4 feet. Wildlife has used them all - all year round.  :)
    Planting round the edges will cover the excess liner. I'd fill it a bit more anyway, and then you'll see the levels better. 
    It's a place where beautiful isn't enough of a word....

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