Barrel Pond gone wrong

[LoveDragonflies]

I set up a half barrel pond about a month ago, using a recycled whiskey half barrel from a supplier online. Bought a bunch of plants and put them in at the right heights etc. it looked lovely for a couple of weeks but for the last two weeks or so it’s gone… putrid. Plants mostly dying off. There’s a weird film on top of the water. It stinks so bad it’s unpleasant to be near. I’ve got a bunch of mosquito larvae and those hoverfly maggots that love “polluted water”, which goes to show how bad it is. Has anyone had this problem and how did you resolve it?

Did you have any aeration such as a little solar fountain? I think ponds need moving water.

Do you have pond weed in the water to aireate it?

I tried this too, it was an abject failure, even with a fountain

No fountain because it shouldn’t need it, eg see this video that inspired me: https://www.bbc.co.uk/programmes/p09jbcl8
I’ve got quite a lot of hornwort in there but I’m not even sure the bunches at the bottom have survived…
Frogbit has rotted as has a water forget me not (I’ve fished them out to try revive them in a separate bucket)
The video makes it look so easy but honestly the smell makes me gag!

Has something fallen in and died?

Erm some insects possibly. Not sure about anything else though as there is a large stick and pile bricks all the way to the top to help things get out.

Did you line it? I would assume there needs to be some kind of barrier. Did you use tap water or rain water to fill it? Rain is best as tap has additives. Ponds also take a while to equalise out into a self contained system and will often have a lot of green blanket weed etc for the first couple of years. I have two small ponds, one in a giant builders bucket, and never needed a pump for aeration. The plants should do that. You also want to be away from full sun, although things like water lily can help shade it.

Hi Harry, thank you. Didn’t line it because so many guides (including the gardnener’s world one I posted) say you don’t need one. These barrels are watertight. I used tap water that had stood for a few days but to be honest, the pond looked great for the first 2-2.5 weeks. It’s only some time after that it’s gone rank and is killing plants etc. Is a bit of sun OK? It gets the morning sun

Currently looks like this:

I would do a change of about half the water and see what difference that makes. Is it under a tree that is shedding leaves, or where grass cuttings or similar could have got in - if you scrap off the bottom of the barrel is there leaf matter. I'm wondering if it could be decomposing leaves.

It has been a very hot summer. It's normal for plants to die off and 'rot' in the autumn. If you can fish out any green slime that helps, but it may all recover and be lovely again by next spring.

Try a bunch of barley straw and/or more aerating plants.

They need a lot of sun. It takes some weeks to get the balance correct with the water..straw bales, for collecting algae. Tap water isn't ideal because of the pH..you need to give it time to settle. Have you got oxygenating plants?

The plants don't look bad. Maybe add another oxygenating plant. You could also empty out a third of the water and let it refill with rainwater.

There’s a little leaf fall but honestly not very much. I fish out everything I see, so only v small bits would decompose in there. There’s also mosquito larvae and bloodworms in there which I think help eat decomposing matter?

I did a barrel pond this summer:

It's still got lots of mosquito larva in it, but it's not stagnant. What i did was:

1. Lined it. I got a pond liner and tacked it to the sides.
2. Dug a hole about half the dept. At the bottom I put a layer of the pond liner (with holes in to let out water) and then a layer of stones. I then put the barrel in and filled the edges with stones too, to make sure it's not next to any soil that might make it rot
3. Put the water in and left it for two weeks to get rid of chlorine etc
4. Put in 2 aerators, and some marginal plants (they're raised on bricks to the right level) and a water lily. I'm not sure that it's deep enough for the water lily, but it's doing okay; no flowers yet, but leaves growing
5. One of the plants came with an accidental free water snail. This seems to have bread so we now have several
6. We have a solar fountain. It's not very good and only goes in full sunlight, so I've got a better one coming to replace it
7. Every morning I check and remove dead leaves/any dead insects
8. Currently the water still looks clear and all the plants (and snails) are thriving

For next spring I'm going to make a ramp in the hope of getting a frog or two!

If it was a whiskey barrel could the whiskey be leeching out of the wood into the water and killing your plants?

I've tried to do this in various containers over the years and always end up with a murky mess. I think container ponds are fraught because the volume of water is so small it heats and cools too much for the plants.

Well, that’s lovely!

Yeah! Nice Houttuynia (I'm guessing.)

We have one in an old butler sink and it’s thrived for 3 years so far. We put a few minnows in it to keep the unwanted larvae away. They ate all the mosquito larvae in no time and don’t bother the tadpoles. Mostly shade is better because too much sun accelerates algae growth.

Also- added 10 tiny water snails and they have reproduced over the years and kept a population going. I believe they cleanse the water and get rid of dead matter.

It probably needed a good few weeks of plain water soaking in it, being tipped out and refilled on repeat several times to get the taint out of the wood first, before trying to use it as a pond.

We dug quite a big pond but it was in the wrong place and never looked nice or got going, it just had too much shade. We filled that in and dug a much smaller pond on the opposite side of the garden and that just consistently looks nice without us really needing to do much, and we get newts. I would move to a sunnier spot and drop some elodea in, get a few bunches off Amazon.
@MargaretThursday i would say that looks a tadge too clean and tidy for frogs. Let some leaf matter get going on the bottom.

Mosquito larvae is a good thing, they're the bottom of the food chain. Ponds take time to get established.

Hi Margaret, what solar fountain are you buying? I also have 3 fairly crap solar fountains and could do with better ones what work when it’s not direct sunlight. Thanks