Pond Boss Forums GENERAL QUESTIONS Muddy water New Pond (Muddy)

I am in SW Mississippi and have a pond that was built in October 2025. Been in a drought and finally received ~7” or rain in past week. Pond is probably 65% full. Pond has been muddy since beginning. Can’t see an inch below surface. It’s due to feeder ditch and lack of grass. Finally getting grass established. My question is I need to clear it up. I put 5lbs of FH minnows in March 3 and they are doing well. I want to clear the pond up some before putting my bream in. I see recommendations for gypsum and/or lime. I started
Looking around for 50 lb bags of gypsum and not easy to find online at Home Depot or Lowe’s or Tractor supply like I thought. The big companies sell at decent price but arm and a leg for shipping. Can someone give me some advice on where I can purchase at a reasonable price? I am in Claiborne County in Mississippi. Any help would appreciated. My pond is approximately 3/4 acre currently and will be about 1-1/4-1/2 when full.

Brian

Brian, I have no experience clearing a pond with gypsum. Don't fall for the bale of straw or barley thing either.

Read the 2 threads in the muddy water section about alum kicking clay's butt.

Sure will. Appreciate the response.

New ponds are often turbid in varying degrees. It often takes several months to a year for a good thick biofilm to establish all over the pond bottom so silty clay is not easily resuspended into the water column. The grassed planted water shed will help a lot to reduce turbidity. Also wave action on the surface embankments contributes to a lot of the shoreline erosion and silt resuspension.

Did you do the jar water settling test to determine if the turbidity does settle out when in the calm conditions?

I have not done the jar test yet. We just received 7” rain in seven days so I plan on doing a ph and alkalinity test as well as a jar test this week. Thanks for response.

Brian

I did the jar test yesterday. I could not get my hands on alum but had gypsum. Jar #1 untreated is still very muddy. Jar #2 with one pinch of gypsum cleared up water in a couple hours. Jar #3 four
Pinches of gypsum turned water really dark, almost black. Jar #4 6-7 pinches of gypsum turned black also.

I tested the water and ph was 6.5-7. Alkalinity was ~10.

I put 400 lbs of gypsum and 500 lbs of ag lime yesterday. Pond is not full yet, 60%. 1/2 to 3/4 acre currently. Will probably be 1-1/4 acre when full. I guess now I will wait and see how it helps clear and moves alkalinity ppm.

Brian

Brian K, you can buy a small test jar of it in the spice section of Walmart, etc. For amounts that are needed in the pond, you need to go to a chemical supplier like Helena Chemical or a place that sells farm fertilizer. Thats's where I get mine. McCormick Alum

How long does it take to expect to see and change in pond appearance after gypsum and lime treatment? Been about 6 days and was just curious.

Gypsum can clear up water in a few days. Several years ago, Todd Overton and I worked over George's sons 3-4 acre pond with gypsum with large dump trucks from Oklahoma. That's the trick because the OK gypsum was pulverized, and is extremely good at spreading. Some of the pond areas even looked milky later. We cut off surface aeration, and the pond was crystal clear in 2 days.

I had set up a rig with tarps, a tractor with a bucket, and a 2" Honda pump and nozzle. We moved the tarps as we hiphoped by blowing the gypsum off the tarps, and not spreading any mud. It worked great, and we got the whole pond done in a couple of hours.

Having said all that, it doesn't all the time. Esshup or others may figure the gypsum/water percent needed. The results of that may show it doesn't work. The second issue is that most of the gypsum in other locations gets gypsum in bags, and most are pellets. Small but pellets, so they don't spread as well. I use those because of the transport expense, and they kind/sorta work, but not as well as aluminum sulfate. I'm thinking about how to cycle gypsum pellets in an IBC tote until they turn to powder.

Thanks. That is exactly what I used was bagged gypsum of very small pellets. Have -approx 3/4 acre pond currently. It’s about 60-65% full. I put 400 lbs gypsum and 500lbs of ag lime. I had done a jar test and one pinch of gypsum cleared the pond water in a couple hours. I used about jar and put four pinches and turned water almost black. So I know gypsum is effective but too much of it will not. I done this last Tuesday and ofcourse it’s rained three good rains since. So still muddy but it’s a lot more volume to clear. I just haven’t measured around pond and checked depth to figure out how many gallons is in pond compared to a pint or quart jar and pinch of gypsum lol. But I did alkalinity and it was 10pm before treatment. And ph was 7.5.

I really appreciate you guys replies. I have read all the different forum topics. Really good stuff.

Brian

I have never used gypsum, only alum.

I may have to end up using alum depending on how results go but after ph test alum was making me nervous since it drops ph even more and alkalinity was already low at 10 ppm. So even more lime would be needed.

Gypsum has pretty low solubility in water. That is the reason powdered gypsum is preferred - due to the massive increase in surface area to be contacted by water.

Do you still have a few pellets? You might try a jar test where you put in a chunk of a bulk pellet that was roughly equal in size to your one pinch that worked previously.

If your pond is not actively accumulating lots of silt or organic muck that would sequester away your gypsum pellets, then you may have created more of a long-term buffer for your pond water. And hopefully your cost and effort still yield you some useful benefits.