Pond Boss Forums GENERAL QUESTIONS Muddy water black water

Our smallest pond is roughly 1/8 acre and 4 feet deep at the deepest point. Last summer we took a back hoe to it and cleaned out the debris and sediment from the bottom. The pond has been borwnish color from the suspended clay for months and now this spring nearly 3/4 of the pond is covered with parrot weed. This week I noticed that the water has turned virtually black. What could be causing this?

Rotting vegetation can cause this. I've had it happen when a pond dried up, grasses grew on the bottom, and then rain refilled it. In my case, it wasn't a huge problem but stocked fish neither thrived nor spawned for a year.

To test it, get some small BG and put them in a minnow bucket. Float them and see what happens.

A worse case was when I put a huge pile of fresh oak trees in for structure. That stuff was lethal and I had to pump the pond dry.

That's probably it. We nearly drained the pond to clean it out and a lot of grass and weeds did grow in it. How long do you think this condition will continue?

Don't know. Mine lasted for over a year. Funny thing; lot of bugs got in/on it with no ill effects.
Test it. If they don't die you really don't have any downside by stocking it.

I agree with Dave that you likely have a vegetation rotting issue. The black water may be from a complete depletion of oxygen and resulting H2S formation (septic conditions). You can raise the pH which reduces the solubility of H2S, or oxidize the water to reduce the septic condition. I assume you do not have fish in the water (if you did and you do have septic water now, they are long gone), you can add bleach to kill off sulfate reducing bacteria and oxidize the water. Take a sample of the water and see if it smells like rotten eggs. If it does, then the guess above may be correct. If you leave the organic debris in the water, then the condition will return till the BOD is reduced sufficiently to sustain sufficient DO to allow aerobic conditions.

I have not stocked the pond. It did have mosquito fish in it and still has a lot of green floating plants in it. There were 2 wood ducks on it this past weekend as well. I'll take a water sample and if needed will treat the water and attempt to reduce any debris. I am in the process of stocking a new, larger pond on the property but was hoping to use this one to breed forage fish. Guess that may have to wait! Thank-you gentlemen.