Hi all! My name is Martin. I and some friends found a quarry in our city. After asking for permision to the land owner, we dove there, water was not clear actually.
So we decided to see if it was posible to make it better. That was 4 years ago.
We installed some ultrasonic devices to control algae. Also we use straw from time to time. We have never used quemicals.
Water visibility has impreed a lot. We have had like 20 feet clear waters. Since last year something is going on we dont understand and we dont have access to someone with knowledge to help us.
A layer of brown water appeared once , right on top of the bottom. It was like 2 meters wide. Cero vis there.
That layer despeared after a couple of months (appeared in summer, desapeared in the winter). This years appeared again in the winter but this time was on the surface. Below this layer water was cristal clear.
We took a sample and made it analice. All we got was that a a Mesophila bacteria was there, not dangerous. I supose that is good...
When water started to got warmer thar brown layer started to "move" to the bottom, and remains there now...
The clear layer water analysis shows water quality is good, ph 7.2/7.5, not amonia, no nh3/2. But int that brown layer there is a really strong sulphur smell. We noticed it when whe dive inside that layer or when I take a sample ina bottle and open it in the surface. Analisys of that water shows sulphur.
I have not been able ti find a place to make a good water analisys to know what is that brown layer.

Can anyone tell me what this is? how to fight it?
Also, thus forum is awesome. A lot of information, can you point me if there is a subforum with articles for reading? I want to learn about the lake quemistry/cycles, etc

This quarry is like 1 acre, 40 feets deep. Temperature now is 23 C till 7 20 feets, then in the brown layer temperature drops to 17C

I hope someone can clarify me the situation.
Question aereation of this brown layer would help?

Thanks in advance,

Martin

Martin,
Welcome to Pond Boss. I'm sure someone will be along soon to help you with your issue. Take some photo's of your quarry when you have time and post them on this site.

Hi Martin and welcome to the forum!

I am not a pro but it sounds like from your description of the brown layer moving from the bottom to the top that you are witnessing what is called a pond turn over. I suspect the frequent applications of straw is contributing organic material to the "brown layer" as it falls to the bottom and begins to decay. If that is the case, then bottom aeration should help. I will leave it to the pros here to give you more informed thoughts and advice.

Good luck and very happy to see you on the forum!

Bill D.

Mesophila bacteria are primarily anaerobic bacteria and are producing the sulphur odor. Brown layer could be stained anoxic water or a type/specie of algae often in the group Chrysophyta. Determining which one will be based on if brown is a true stain or color of the water or from microscopic solids(microalgae - golden browns) in the water.

Great information! I have seen with a microscope. It look like yes: it is a bacteria and also a king of brown algae is there.
What would be your advise for better determine what it is and posible ways of ifght this? aiereation?

Adequate aeration would mix the water column and expose the lower water to the surface to add oxygen.

IF your bacteria is anaerobic bacteria then aeration will cure your problem.

A high density of anaerobic Mesophila bacteria could be causing a hue to the water. I am not familiar with all the various colors of bacteria. You do recognize the difference between bacteria and very small nanoplankton algae in the 3-5um size range?

No. But what I saw at the micrscope was much bigger than 5um, so I assumed it was algae. The water laboratory sent a picture of a petri box showing the bacteria, and that bacteria colony had a brown color.
Any suggestions about how to get more specific data will be preciated. Also, if you need any more data I have the water analysis with quemical data.

So the sulphur smell is caused by the sulphur produced by this bacteria?

Organism particles larger than 5um would be certainly algae if they have symmetry and apparent organized structure. Planktonic protozoa rarely get dense enough to color the water, but it is possible. The water could have bacteria and algae in it, both contributing to the color. Sulphur odor is caused solely by the bacteria. They produce sulphur as a by-product of their anaerobic activity. The brown layer with odor directly next to the bottom will most likely be the result of anaerobic activity. It will contain no dissolved oxygen and can be verified by opening a bottle in this area/zone, allowing it to fill with water, capping it, then testing the water for dissolved oxygen.

What is the water temperature close to the bottom??

Others are correct, Bottom aeration sized, located, and operated properly will eliminate the sulphur smell and brown water layer that is next to the bottom. Bottom aeration if operated continuously will also make the water very similar temperature top to bottom all within 1-3 decrees C. Aeration may or may not make the overall water top to bottom clearer - higher visibility.

I feel really lucky.... this forum is awesome, lot of people with some much knowledge about ponds/lake. I have learn from reading posts here in the last 24 hs A LOT of things that will help me with this quarry.
Thank you VERY MUCH!

I will look for some aireation method I can use in the quarry. Suggestions? electricity is not available in the quarry.

How far away is electric? You can run 2-4cm airline for a KM or two....

Like... yes, may be 1,xxx km away. What do you mean with a 2-4 cms airline for a KM????

I have run airline underground from an electric compressor for around 1,500 meters just to get to the pond, then another 300-400 meters once the line was in the pond to the diffusers. I can dig up the data if you need.

That would help me, thank you very much. What type of compressor did you used? You run it 24hs?

It's used to prevent winterkill in a clients pond, his pond is shallow enough that it isn't needed during the summer. During the winter it runs 24/7.

It is this system:

http://www.vertexwaterfeatures.com/sites/default/files/Air-5-XL2_0.pdf

Have you considered wind power? Some of the newer wind aeration systems have greatly improved on the old style windmills.

BTW, welcome to Pond Boss.

Martin I had an anaerobic condition similar to yours and windmill aeration has worked for me. Keep in mind no two ponds are the same. What the aeration does is cause water at the bottom of the pond to lift to the surface where it will release gases and gain oxygen. So you are mixing your pond water and the layers you see should reduce along with the sulfur smell. IMO aeration is the best thing you can do for a pond.

I will look for info about those equipents...