Stagnant mini pond- help needed!

[hannah2339]

Hi there,

I need some help as I am a complete pond novice.... This is my first ever post, apologies that it's quite long!

We recently moved into a new flat and it has a stagnant pond (see pictures) down the end of the garden. The water in pond was really polluted, dark green in colour and smelt foul. I got the water on my hands earlier and I still can't wash the smell off- that's how dirty it is. I couldn't imagine that anything was alive in there as it was so filthy.

This afternoon I decided to start emptying it out, a bucket at a time. I didn't think I could have it as a functional pond (no filter/drainage etc) so I thought I'd turn it into a herb garden. Whilst doing this, I uncovered some frog spawn - which was a big surprise. Removing a few buckets of water had exposed it so I couldn't leave it there.

I've taken the frogspawn into the house and assume they will probably hatch quite quickly. I need to sort the pond out in the meantime as they'll need to go back in there once they hatch. I think I also saw a newt in there earlier when I was finishing the frogspawn out, so there is obviously a lot more in there than I thought - I can't see anything though as the water is dark green. So my questions are:

1. How do I go about emptying the rest of the pond without killing the wildlife in it? The water is so bad I don't think I can put the frog spawn back in there with it like this. Also it is half empty.

2. What kind of water should I be replacing the bad water with? Should I do it in one go or a bit at a time?

3. Do I need a filter? Drainage? A net over the top? I know nothing about ponds but am keen to learn

4. I heard that frogs will need stones up the side of the pond to get in and out with, what is the best approach with this?

I would really appreciate any help and thanks for taking the time to read this!

[King Edward]

How long/deep is the pond?

I think the best thing to do would be to empty the pond completely, removing all the water, decaying leaves / gunk at the bottom, rescuing any newts or other creatures in the process, and then refill it. Newts would be OK released into the undergrowth.

Rainwater would be best, failing that tapwater would be OK but let it stand for a day or two before returning the spawn. Frogs are happy to lay in even very small water bodies, and Smooth Newts should do OK as well, so cleaned up and with some appropriate water plants it could be quite a good habitat in the garden.

I'd also be inclined to remove the white rocks around the edge, in fill with soil (below the level of the rim, so the rain doesn't wash soil in which would pollute the water) and plant with low-growing but dense plants to provide some cover around the edge without shading the water (herbs like mint might be good).

You don't need any filter or pump - a mesh on top might be useful in autumn to catch leaves, but it's not essential and not for the rest of the year. Be careful with netting (probably best avoided) as it can trap small creatures.

If the water level is kept high then frogs/newts should be able to get in and out, but it might be a good idea to put in some stones/bricks at one end to provide an underwater step/slope in case any hedgehogs etc. fall in so that they can get out.

I'm sure other people will provide further advice.

[Tursiops2]

God what a hideous construction . Whoever put that in had more money than taste, what a shame you've been lumbered with it.

I can't add much to King Edwards suggestions. Replacing the stones with plants will improve its appearance as well as making it a bit more wildlife friendly. Perhaps fast-growing annuals like Alyssum, Phacelia or Limnanthes for this summer. A few oxygenating plants in the water should improve conditions for the tadpoles.

In the longer term, if you don't want to keep it as a pond (it could be improved, to some extent), a herb bed is a good idea. Perhaps next winter you could put a better-designed pond somewhere else in the garden?
T2

[hannah2339]

Thanks for the good advice from both of you - really appreciate it.

King Edward, the dimensions are:

102cm long
43cm wide
37cm deep

There is a shelf on one side half way down but I can make this a bit higher with bricks.

As you can see, it's pretty small but I do think there is quite a lot in there as there was definitely stuff moving about when I was measuring the depth.

That's a great idea about removing the stones and replacing with some plants. I will look into that straight away, thanks for the suggestions.

Just a couple more questions:

1.When I empty the pond, should I line it with something?
2. Any suggestions about what kind of pond plants I should buy? Don't know anything about them - are they rooted or do they float? If they're rooted, what do I need to put in the bottom?
3. If there's no filter, how do I stop the algae taking over and keep it clean? Is there something I need to put in the water?

T2, unfortunately wouldn't be able to put a different pond in somewhere else as it's a rented flat. But hopefully I can get this one looking and smelling a bit better!

[Tringa]

Agree with the idea of cleaning out now.

There will be no problem if you use tap water. We emptied, cleaned and refilled our pond with tap water last June. The frogs moved back in very quickly and now the pond is full of spawn, but perhaps giving it a few days before you put spawn back in may be a good idea.

No need to line the pond. As it is a small pond be careful not to get plants that are too big. Google for plants for wildlife ponds. Some oxygenating plants would be useful. Ponds become yucky because of excess of nutrients and main causes are soil washing in and fish waste (which isn't a problem with your pond). Plants in the pond will use up nutrients. We have found ordinary supermarket watercress useful. It grows well and if it gets too invasive it is easy to remove.

I've also found The Rock & Water Garden Expert by Dr D G Hessayon a very useful guide

[Tursiops2]

Originally Posted by hannah2339

T2, unfortunately wouldn't be able to put a different pond in somewhere else as it's a rented flat. But hopefully I can get this one looking and smelling a bit better!

Fair enough, I thought that might be the case.

if you want to improve it for the long term, this is what I suggest:

Download this pdf from Natural England: NE27 - Garden ponds and boggy areas: havens for wildlife
It has a comprehensive list of native pond plants, categorised according to their suitability for different sized ponds. Please also note what it says about using invasive non-native plants.

I would suggest that, rather than removing all the stones completely, it would be better to remove all the stones to the rear of the pond, and only about 30% - 40% of the stones at the front. Placed across a patio like that, the pond is a potential ankle-breaker, and at least the white stones make it more conspicuous at night (make sure you remove the stones that are falling down the sides of the pond).

Don't throw the stones you remove away - water-rounded pebbles aren't exactly cheap - but re-use them elsewhere. You could use a few to make a "ramp" in the pond.

Plant Thyme and Wild Strawberry into the gaps at the front, with denser planting of herbs etc. to the rear. You could also plant one of the small-leaved ivy varieties and train the stems along the rim of the pond.

Consider building a small log-pile in the vegetation to the side of the pond, this will create hiding places for frogs and newts.

Have a read through this thread: Building a new pond Note particularly the use of old tights to make planting pockets, and the discussion about suitable Ivy varieties.

You've potentially got a nice little wildlife feature there, even if it is appallingly sited . At least you didn't have to pay to get those slabs cut .

ATB
T2

[tom00_uk]

pile some of the stone up in a corner to provide a way for things to get out of the water,
plant up with low slow growing plants if possible and provide some cover at the point where the flower bed is closest to the water body,

unfortunately when it was installed it was set up so the shallow end is furthest away from cover of the flower bed

if you dont have enough rainwater to top up when done, then if you must resort to tapwater make sure you add a tapsafe product first to try and reduce the chemical load from making the water fit for human consumption

[~T~]

Some good suggestions. I like the idea of replacing the stones with plants to make it more wildlife friendly (and also more aesthetically pleasing). I wouldn't put any of the stones in the pond as the more you put in the less room for things to live. If you are worried about things falling in and not being able to climb out you could always position a small branch half in/out of the pond.

[hannah2339]

this is great, thanks to all of you for your advice. I'm definitely starting to get a bit more clued up about this now...

I've looked over everything that you've all suggested and made a plan:

1. Clean out the pond and refill with tap water (unfortunately this is all I have). I will fill up as many buckets of water as possible and stand them outside for a few days first. The rest of the water will have to come straight from the hose unfortunately. I'll have a look and see if i can get hold of a tapsafe product. Can i put all the creatures I rescue straight into the tap water or is this a bad idea? i won't put the spawn back in for a few days

2. Remove most of the rocks, I'll use few of them and some sticks to build a small ramp along out the pond. I'll leave some rocks around the sides and add some soil along with the plants what you suggested T2. thanks for that

3. Get some watercress as suggested by Tringa and some yellow flag iris - I heard this is good to help with the algae? I'll get researching on other appropriate pond plants

4. Build up some cover (stones, logs etc) next to the pond for a hiding place

Again, thanks for all the help - I'll be sure to let you all know how I get on.

[King Edward]

I'd just fill the pond straight up from the hose - in a few days it'll settle down anyhow. Any small pond creatures could go in with the frogspawn until you return it, and any frogs/newts could be put into the garden undergrowth so long as there's shelter there - they can return to the pond whenever they want.

The white pepples look a bit small, so I think you'd be better with 2 or 3 larger garden stones to make a step up out of the water. It doesn't have to be a big ramp up from the bottom, just something to help creatures get out of the water and over the lip of the pond. If you can get some plants trailing into the pond from the sides, that would help as well in time.

Yellow Flag is a nice plant to have, but it is very vigorous growing and I think would be too big for such a small pond. Once it gets establishes, you'd be forever trying to restrain it. One of the smaller (non-native) water irises such as Iris laevigata might be better in this case. Alternatively, for marginal plants you could try Arrowhead and Flowering Rush. The plants suggested by the pdf linked by Tursiops2 are good, which indicates those species most suitable for small ponds.