Green pond water.

[Sheila Jones]

Hello. I have a 2/3 year old pond, 30' x 20' kidney shaped, 5' and 4' deep. There are no fish only plants. Most of the plants have died and the water is pea green and thick. Really want to sort this out. Has anyone any ideas please. I tested it for nitrate, nitrite, ammonia and pH today and all is normal. There is a little frogspawn in it at the moment and I have seen great diving beetles and snails in it once.

 

[Meyer Jordan]

How much organic matter has accumulated on the bottom? If most of the plants have died it was likely a result of a paucity of nutrients. Had you fertilized the plants in the past? Without fish, plants need a supplemental source of nutrients.
This may be a good time for a clean-out. Then you can replace the plants and begin a fertilizing protocol.

 

[Sheila Jones]

How much organic matter has accumulated on the bottom? If most of the plants have died it was likely a result of a paucity of nutrients. Had you fertilized the plants in the past? Without fish, plants need a supplemental source of nutrients.
This may be a good time for a clean-out. Then you can replace the plants and begin a fertilizing protocol.

Thank you Meyer for the reply. Sometimes there are yucky green blobs coming up from the bottom so a clean out might be a good idea. I didn't know about fertilising plants. The pond was done for us by a professional local company and the plants also put in at a considerable cost! Will read up on plant care more and see what we can do. I am determined to get a beautiful pond some day.

 

[Lisak1]

@Meyer Jordan - just a general question that might apply here : would rotting organic material in a pond not provide nutrients to the plants, the same way we use composted material in a garden?

 

[MitchM]

That's a fairly large size for for a plant only.
It must be a fairly elaborate setup.
Can you provide any pictures?
What is the water circulation like?
Were the plants placed in any kind of substrate?

Something's not right if it only took 2 or 3 years to turn into pea soup.

Decaying plant matter will deplete the water of oxygen and supply algae with nitrogen and phosphate.
Alage will out compete more complex plants in that case.

.

 

[Lisak1]

Decaying plant matter will deplete the water of oxygen and supply algae with nitrogen and phosphate.
Alage will out compete more complex plants in that case.

Ah! Thanks - I've often wondered about that. Although I would imagine the result would be different in a natural pond? Scale must play some role, right?

 

[addy1]

Welcome to our group.

Pictures will really help. And do you have a filter or circulation of some sort, like Mitch states above.

 

[Lisak1]

@addy1 - you're always so good about remembering the Welcome! I sometimes forget and just jump right into problem solving mode!

So @Sheila Jones WELCOME!

 

[addy1]

lol I try to remember!

 

[Meyer Jordan]

@Meyer Jordan - just a general question that might apply here : would rotting organic material in a pond not provide nutrients to the plants, the same way we use composted material in a garden?

Yes.....but! Compost is used as both a natural fertilizer and also as a soil conditioner. Once the Nitrogen, Phosphorus and Potash is depleted (usually one growing season or less), what is left are other organic compounds including cellulose and lignins which are quite slow to break down and thus "condition the soil". The same process applies in aquatic venues, The 'Muck' that accumulates at the bottom of ponds is quickly devoid of Nitrogen (Phosphorus may take a little longer depending on the particular pond) leaving other slow decaying organic matter which will accumulate as what is termed 'Muck'. Left alone this 'Muck' will continue to accumulate, eventually (many, many years) filling in the pond.

 

[MitchM]

... Scale must play some role, right?

Scale is scale, I think relative value is a better way to look at it.
A larger body of water will give you more buffering capacity against fast swings in the chemistry but if you have a large amount of decaying plant matter relative to the water volume, things can go wrong just as quickly.
Bigger messes are more physical work to clean up of course.