Pond Boss Forums GENERAL QUESTIONS Water chemistry Why is the water black?

I went down to the pond and the water was black. How can I get the water clear again and will it hurt my trout?

How about a photo?

Take a sample in a clear glass (mason jar). Then put it in front of a white background and take a picture.

Are there leaves that fall into the pond? And if so what kinds of trees are they.

Smallpond -- it is just that time of year. My main pond and my larger grow-out pond went from greenish/murky, to very clear, to very blackish-clear in the last couple of weeks.

We are getting into the 30s and 40s most nights lately, which I assume you are also. That has diminished much of the biology in the pond water. With all of the hardwood trees we have in this area, especially all of the oaks, they add a lot of tannin to the water. Tannins will precipitate a lot protein and other organics from your water, making it relatively clear -- but much like tea leafs, it will also color it a very dark color.

It is a natural occurrence in our area of the Appalachians. The trout will actually love it and flourish in it.

Is the area a bog/acidic/mine runoff ? If it is then ag lime will help with the color and acidity. Need to test the water.

Maybe Sunil will see this thread. I think his pond is fairly close to Smallpond's pond.

What does Sunil's pond look like at this time of year? I'm about 75 air-miles away from either. I'm at a similar altitude, with mostly the same kinds of trees. My ponds go through many different stages every year.

A water test can certainly tell a lot. But, my guess is that by the time you figure out what your pond is doing today -- it will be doing something totally different in the next seven to ten days.

Water tests are pretty cheap if you're wondering. If you haven't done one yet, might be a good time to do it. Lusk suggests doing seasonal (quarterly) tests to track trends.

I suggest that you fill a white 5 gal bucket with the "black" water and post a picture of it.

It looks like suspended particles of hydrogen sulfide laced sediments. Anything in the pond to stir or resuspend anoxic sediments?. Maybe put some in a two liter soda bottle cap it and after a couple/several hours smell the overlying air. Air should stink if the black is due to hydrogen sulfide.

Hydrogen sulphide is extremely toxic. Have you experienced any fish mortality?

OK Thankyou for the advice I'll put some pond water in a soda bottle let it sit for awhile and then see if it stinks.

Tho I haven't seen any morts lately the water isn't very clear so I really don't know wether any died or not. What would kill over first the CC or BRKT?

I did a little searching for information on toxicity of H2S to trout and catfish. Generally channel catfish are a lot more tolerant (33 times more) to H2S compared to trout. Trout will die a lot quicker from hydrogen sulfide poisoning compared to catfish. If the problem was hydrogen sulfide and the trout died and catfish lived the H2S concentration was above 0.007ppm and less than 0.5-0.8 ppm. temperature and pH play rolls in toxicity of H2S to fish and invertebrates.

I did the bottle test and the water didn't have any smell at all, since then the water has returned to it's natural color.

Depends on the ph. Virtually no effect on my fish at a ph of 8.6.

Small Pond,

Are your brookies cruising the shoreline,jumping and exhibiting challenges to each other? Maybe this could stir up sediments?

Some of mine are doing the above and I'm sure it's due to spawning behavior. Hopefully I don't have any females as this could up the antagonism a notch. I paid extra for all males. Hopefully they are.

True.

Hydrogen sulfide gas can dilute and dissipate faster than the black stain. If you didn't loose any trout then the H2S was not concentrated enough to kill trout assuming the color was due to hydrogen sulfide.

Get the water tested and don't guess about cause and effect. If its H2S or acid which I suspect then add some ag lime to offset the problem.

Speaking of H2s, could that be what the bubbles are coming from the bottom of my pond? Pond is about a year and a half old. Not lots of bubbles but have always noticed a few since the pond was new.

We are in an area with shallow coal seams and some shale. Never hit any while digging the pond but I wondered if a coal seam could be deeper and offgasing a little...... methane??? Or is it just a normal occurrence to see a few bubbles coming from the bottom in a pond?

Just curious. Doesn't seem to have harmed anything that I know of.

snrub

I've seen methane bubbles in "normal" bodies of water.

Me too but only after a few years accumulation of muck (leaves , dead plankton , etc).

It is possible that gas is escaping to the surface from fractured or faulted coal or oil and gas deposits. There are countless locations around the globe where that occurs including many in the US and all the oceans.

There is a pond near me with constant slow small upwelling of methane bubbles. It is enough to keep a small open hole during ice accumulations up to 2"-3" thick.

So glad you did not have a fish kill,SP. You live in coal country so you are apt to have discolored water at times. This can happen at high water or low water occasions. Ag. lime is one thing you can add(as per Ewest) and I am sure with your know-how and work ethic you will conquer any obstacle in your way. Take care.