Pond Boss Forums INTRO Questions & Observations Murky water in a clay based pond

Hello,

Last year i dug a small 1/4 acre pond which is clay based and is approximately 14 feet in depth, The water has never become clear, and people have told me that this is due to clay particles suspended in the water. I have also heard that adding gypsum, limestone, or certain types of straw can clear the water up. Does anyone have any info on this? or had sucess with any of the above? and if so how long will it work for?

thanks guys!

RB

I would suggest looking under General Questions & Muddy Water
Also do a search for Muddy water.
Lots of post on the subject!

Aquatic Control in Seymour, Indiana, 1-800-753-LAKE, URL www.aquaticcontrol.com, sells a product called "Lake Kleerant" which is aluminum sulfate. It includes baking soda for addition as a "part B" to keep the pond from becoming too acidic. You dissolve it in water and broadcast it over the surface of the pond. I had a clay pond with essentially zero visibility due to ionically suspended clay. I applied the aluminum sulfate, and within a day or two had several feet of visibility. It has since stabilized at about 3', which I consider plenty.

I had a similar size pond dug here in Michigan 4 years ago, it too was clay. My pond took about 2 years to clear up. I tried the gypsum thing and watched water in a jar, but the only thing that helped was time and getting the shoreline seeded to hold back sediment when it rains. Since I have had decent grass and clover growing around the pond washing in clay during rain storms is no longer a problem. I know it's hard, but be patient, it will clear-up with time. Note: my pond is not crystal clear, but clarity to a depth of about 2 feet is very good.

RBC,

Gypsum probably didn't work in your pond because your water is already quite hard with plenty of calcium carbonate. I have seen literature that says ponds like this don't respond well to gypsum. Here in northern Indiana we have similar water to many parts of Michigan and gypsum won't help here. I'll bet Aluminum sulfate would have worked better and you wouldn't have had to wait. However of course you did right. Stopping the cause of the problem is essential as if you don't you are only treating the symptoms and the problem will come back.

I will be treating another one of my ponds in a few days with aluminum sulfate that has plenty of grass cover etc. around it and had never been turbid from clay in the nine years I have had it except when I first put it in and it was filling. It has no erosion either and is fed with well water from my trout pond. Apparently sustained high winds this spring beat the hell out of the windward side of the pond even with the plants, and resulted in suspended clay.

Here is something to consider: I was able to locate aluminum sulfate in 50 lb. bags from a local chemical supplier at only just over $11.00 per bag. No shipping costs!I doubt I will even have to buffer as my alkalinty is very, very high. Small scale tests in a jar did not even phase the PH.

Aluminum Sulfate is also called Alum, which can be usually purchased from or through your local water treatment plant guys. It is used in water trmnt to settle out suspended particles causing the stuff to 'clump', and then fall to the bottom.

Here's the scientific explanation: "These chemicals are known as coagulants. A commonly used coagulant is aluminum sulfate, or alum. In water, alum forms sticky globs, called flocs, that attach themselves to bacteria mud and other impurities. The water is then pumped into a settling basin where the flocs and contaminants sink to the bottom. This step removes most impurities.

Cecil, your observation that high winds were enough to cause clay to go into suspension is interesting--were you able to see any erosion around the banks? RBC, I'd read that once the stuff is in suspension it physically can't settle out; I wonder if what you had was just enough constant disturbance from fish, etc. that it stayed murky, rather than ever clearing; I do know that the reaction to addition of alum in our pond was quite striking! (And Cecil, thanks again for guiding me through that a couple of years ago on farmponds.com--ever in your debt).

Inland Island, So could I get even more clearity in my water by adding some aluminum sulfate? What is the affect on fish, and what are the normal application methods and rates?

RBC, it sounds like Cecil thinks so; since I've never used gypsum I don't know how to compare. An easy test: Go to the drug store and get a jar of alum (which is aluminum sulfate); get a couple of big jars full of pond water; put some of the alum in one; let the two sit and see what happens. If the alum one gets clarified, then aluminum sulfate will help. If you decide to use it, mix it up in a stock tank and add it throughout the pond. And if you can get it for $11/100 lbs by all means do so!!

I'll also confirm what Cecil said about high winds turning up sediment particles in a pond but also the temperature of the rains. Last week we has a few storms come through with some outrageously high sustained winds and very cold showers.

It had rained alot the previous week and no change was seen in water clarity, other than a few inches. The bloom kept coming back, even after a few days of rain.

Anyways last week, with the storms coming through, the outdoor temperature alone dropped down to 59 and 57 during the showers from highs in the day up to mid 80s. Keep in mind I'm in the deep south, its practically almost summertime, and yet you could see the heat from the pond misting up through the much colder air. The pond not being in any protective area anyways is always moving due to any amount of wind, but after these, the pond turned brown. Its almost a 30 year old pond, however mostly drained in 2002 to rotenone and restock. There is no erosion or silt to wash in from anywhere, and due to the fact that the rains were less that the previous week.

I believe my newly suspended particles were due to the high winds mostly, but possibly as well due to much colder waters from the rains (low to mid 50s) that infiltrated the pond that was at a water temperature of approximately 80 - 85.

Its been over a week and its all still suspended, I don't believe it was a plankton die off as the bloom is still visibly growing on the surface in places. Perhaps the cold water did cause some of it to die off. All I know is that it has been a stressful week coming to this conclusion.

RBC,

Go to these two sites that do a good job of explaining the use of Aluminum sulfate (alum). One of the sites also discusses the use of Gypsum and how to test to see how much you need of either one of these two compounds.

http://agfacts.tamu.edu/D11/Calhoun/Mar/Recfish/Pondmgt/mudpond.htm

http://www.perigee.net/~jrjohns/aluma.html

As is explained on the first site there is a specific jar test to do to determine how much alum you need. Alum is harmless to your fish by itself. The danger is too much or too quick of a PH drop if your alkalinity is not high enough to buffer the Alum which is acidic.

The alum for just over $11.00 was not in 100 lb. bags it was 50 lb. bags. Still much better than ordering it!

Last time I used alum I made a "slurry" (mixed pond water and the alum in a plastic garbage cans) out of it and broadcast it over the small 1/10th acre pond via a plastic lemonade pitcher. However the pond I want to use it on now is .62 acres and requires about 300 lbs. I may broadcast the dry crystals on a calm day instead of mixing the slurry as it will be a lot of mixing for a pond this size. I was told by an extension agent I can spread the crystals on a calm day. Not sure if I will as I am skeptical of this but it's an option.

JM,
Sounds like to me your pond turned over due to the input of cold rain water.
Do you aerate?
If not the low DO water in the bottom of the pond could have killed your bloom when it was displaced by the rain water & mixed with your surface water.
Just a thought.

Ric,
No aeration system in place on my pond. The winds hit this thing so much I don't really think its needed all that much. The more I think about it, I'm leaning towards that it was a combination of both the high winds and the cold water. Sort of a mixture of some dead plankton and suspended particles. I do know that a bloom is attempting to come back on the sunny days we've been having, but it appears to be clearing up slightly. My visibility is about up to 12 or 14" with a good pair of eyes. The sunfish only appear to bite now if the hook is dropped right in front of their little eyes, that sorta lets me know that the particles are suspended throughout still. However they haven't forgotten where and when dinner time is.

Still haven't seen any dead or gasping fish in the morning, so thats a good sign I suppose. The winds even on a calm day move the water very efficiently. For instance, if the wind is blowing constantly here as it usually does during the day, You can't paddle the little 14 foot jon boat across the pond, as the wind will take you where its blowing. I'm thinking that the wind may be the only thing keeping Oxygen in the water right now. But I don't know if thats a fact or just wishful thinking on my part.

JM--I don't buy the theory that wind is keeping oxygen dissolved throughout the water column. However, I do think that your abundance of breeze would make a windmill aerator very practical for your pond, a fact of which I am jealous. They're pretty cheap, attractive if you like that sort of thing, a conversation starter and free to operate!!

I've thought about the windmill aerator for just that reason as well. Its just finding the proper place for it.