Pond Boss
Posted By: bigfrog Calculating Gypsum Amount - 05/24/05 01:10 PM
Have lurked on this site for some time and appreciate all the good information available. I have had ponds for several years and have Mr. Lusk's Basic Pond Management to thank for the enjoyment I have had in managing them to this point. I am in the process of using the information gathered on this site to clear a muddy pond in SE Missouri. Pond is 4 years old, supports a nice population of channel cat and hybrid bluegill, but has never cleared. Letting water sit undisturbed does not result in clearing, so I do not suspect the catfish or runoff problems to be involved. Adding a half tablespoon of of gypsum to a gallon jug of the water sample works great. Noticable improvement occurred within a couple hours and within 12 hours the water was clear. The pond covers approximately 1 surface acre with a maximum depth of about 15'. What I need to know is how much total gypsum to buy and disburse. I found links to articles giving recommendations based on adding gypsum in a slurry to the water sample, but I just added the powdered gypsum directly to my one gallon jar. Can someone provide information on how much gypsum would be needed for my pond based on its size and the half tablespoon per gallon yielding good results?

Thank you.
Posted By: Meadowlark Re: Calculating Gypsum Amount - 05/24/05 01:22 PM
bigfrog,

I can't help you on the amount of gypsum, but can suggest an alternative option that has worked well for me. A soil test would be preferable first to determine the amount of lime needed, but its probably on the order of 5 tons.

Just call your local feed store/coop that handles pasture liming and order 5 tons and have the spreader truck put as much as possible in the pond itself and in the surrounding immediate drainage area. Your water clearity problems will be fixed for many years, minimum expense, and no real hard work involved. Its just another option to consider.
Posted By: bigfrog Re: Calculating Gypsum Amount - 05/26/05 06:47 PM
Thank you for the reply Meadowlark. I will look further into that option. I am curious how soon you have seen results using this method and wanted to make sure that you felt this was a good option for suspended clay in the water.

I haven't heard from others yet on the Gypsum amount, so I am continuing to investigate on my own. I think I may have erred by putting way too much (1/2 Tablespoon) in the one gallon of water. The results were dramatic and exactly what I wanted. However, I did some conversions from acre-feet to gallons and then from using the weight of gypsum per known volume to the weight per 1/2 tablespoon, and am thinking now that I may have added almost 10X a normal application. I am continuing to work on this by adding gypsum to another gallon using smaller, carefully weighed amounts. I'm using grains because I have a fairly accurate scale that is used for reloading ammo. So far, I have not seen the water clear and I have added 20 grains to the gallon. I am hoping to see the clay "clump" and drop out soon. Thanks again for the post.
Posted By: h20fwlkillr Re: Calculating Gypsum Amount - 05/26/05 07:10 PM
A Much cheaper fix for your muddy conditions is one the MDC gave to me. Take a quart jar of your pond water. Add one tablespoon of vinegar. If your water clears within 24 hours this will work. You will need 4 small square bales of good fresh alfalfa hay. Place bales at points around your pond, no need to bust bales open just stake in 2-3 feet of water. As the hay decomposes it releases a mild acid much like in vinegar that allows the clay particles to settle. You can reapply the hay in 3-6 weeks if the first treatment didn't clear the water, but do not use more than 2 treatments a year and do not treat in the summer. Oxygen depletion may occur.
Posted By: Meadowlark Re: Calculating Gypsum Amount - 05/26/05 07:45 PM
bigfrog,

The ag lime treatment isn't an overnight fix...much slower and much more long lasting than other options. I'd say you will see clear water within a month of treatment, but that's subject to your conditions of course....and it should last you at least 5 years.
Posted By: bigfrog Re: Calculating Gypsum Amount - 05/27/05 08:46 PM
Update on muddy water. The gallon jug with 20 grains of Gypsum is beginning to clear. After about 24 hours, there was substantial clay sediment in the bottom of the jar and the water was much clearer. I am hoping it may clear a bit more yet. The vinegar has not cleared the water yet, but I am not sure what timeline to expect, so I'll continue to monitor that in the hope that the hay solution might help. My next step will be to try to get some better measurements on the pond itself to make sure that I am accurately estimating the volume. I live in a agricultural area, so I may lime the area around the pond and use gypsum or hay to get some quick clearing. Lime, gypsum and hay are plentiful and available locally. I'll post another update later. Thanks again for the replies and help.
Posted By: h20fwlkillr Re: Calculating Gypsum Amount - 05/28/05 08:02 AM
The vinegar should work in 24-36 hours. If it doesn't the hay won't work.
Posted By: bigfrog Re: Calculating Gypsum Amount - 03/29/06 09:25 PM
Another Update as Promised -- In June of 2005, after further experiments with minimum numbers of grains of gypsum per gallon that would clear the water and my calculations for volume of water in my pond, I spread about 2500 lbs of Gypsum using the boat and shovel method. The results were great. Within a week, my visibility went from just under 6" to about 24" with a gray-green cast to the water as opposed to the "weak coffee" color. It was great watching the fish attack the feed and be able to see what was doing the feeding for once. Now for the bad news. The clarity did not hold. We went through a minor drought which exposed about 24" of clay around the perimeter during the summer. I waited until now to post thinking that after the level was restored and the catfish were less active, it might settle again. It has not. I now suspect that I may have had two issues if that is possible. One, chemically suspended clay particles along with some physically suspended clay particles. In retrospect, my test jars would never clear, but I would notice some sediment in the bottom after a couple weeks. I suspect the new physically suspended clay may have come from a combination of exposed shoreline (since the water had been so turbid, there was no shallow vegetation) and the higher rates of activity others have referenced in catfish ponds during the summer months. I am now in a re-grouping phase wondering what my next plan of attack should be. It appears to me that the reintroduction of the clay has resulted in additional chemically suspended clay since the water level is now such that there is no exposed shoreline and I would assume the catfish are less active. I have measured a PH of 8.5 and have been told water hardness is high in this area. I am considering Alum, but still reading prior posts on that method. I have a larger pond that I do not plan to put catfish in that is currently filling and it is currently quite muddy too. I know I will need to solve this problem before I stock this new pond with Bass (Native Bluegill and Fatheads stocked last week). I hope this information will be helpful to others and welcome any additional suggestions.
Posted By: Dave Davidson Re: Calculating Gypsum Amount - 04/04/06 05:49 PM
Bigfrog, have you taken any more steps to clear the water?

Both of my one acre ponds are pretty turbid. Since this is a new, never before, condition I have no reason to believe that anything chemical has occurred. Water level has dropped considerably as has the size. Wind on one and catfish in another may be the culprits. Since they are now between 1/2 and 2/3 acre, I'm thinking of starting with about 150 lbs of gyp on each to see what happens.
Posted By: bigfrog Re: Calculating Gypsum Amount - 04/05/06 02:08 PM
Yes, a little bit, though not as carefully thought out (or carried out) as my original effort. Since the water level is restored and there is no exposed shoreline now, I wanted to see if there was any chance if I could get the visibility back that it would hold better. When I put the original gypsum in, I had a dump truck drop the load near the edge of the pond. There was quite a bit remaining in this pile, so I took a tractor with a front loader and scooped about a 1/4 bucket per scoop and dropped it at different points all around the edges of the pond (Yes, I was lazy.). The net result is that to the eye, it appears that I do have a little bit more clarity. However, the results were not nearly as dramatic as with the full 2500 lbs of gypsum and the spread application. The only other thing I am doing is watching the clarity in my new pond which has yet to fill. The new pond is just across a hillside, and the water looks just like the pond I have been trying to clear. Once the new pond gets full, I am anxious to see if the water will clear (either naturally or with my help) and if so, if it will stay clear in the absence of catfish. To me, if the new pond can clear and hold clarity, this will lend support to the idea that the action of the catfish may be the culprit in the current pond. Other factors such as soil type, pond construction, ph of water, etc., are nearly identical. From my experience, which is very limited, from your post above, it seems like the amount you are considering might be a bit low. I know from my jar tests and from reading here on the forum that a little bit of gypsum does not do a little bit of good. It takes a certain amount to reach a critical threshold and then boom...it does its work. However, from earlier posts I have read the advice to put in a little, then a little more, etc., until you reach the amount that is needed to force the suspended clay to clump and drop out of suspension. What you might consider is doing basically the same thing that you are considering in a test jar. While others have used a slurry method and applied to test jars, I was able to get good test jar results just by dropping in very small quantities of gypsum directly to a gallon jar. If the purpose of your test is to see if gypsum might have an effect on your turbidity, I think it would be easier to add enough gypsum to give you a positive test (clear water result) in the test container. I'm thinking that if you put in 150 lbs, then 300 lbs, etc, you might not get a positive result in your pond and so conclude that gypsum was ineffective. However, if you drop in 1/8 tablespoon, then 1/4 tablespoon, etc., you might get a good result and know that gypsum is the ticket, and then just have to determine how much to add to the pond. I hope to hear back from you and others as I am still battling this problem here.
Posted By: adeoghert Re: Calculating Gypsum Amount - 04/05/06 04:36 PM
bigfrog,

What about adding both lime and gypsum?
Posted By: bigfrog Re: Calculating Gypsum Amount - 04/06/06 03:13 PM
adeoghert,

I think that might be a good plan. We did apply lime to the pond construction area of both ponds. The amount of lime was based on the NRCS soil test that was done prior to construction. The only thing I haven't tried yet (and may yet when the pasture surrounding the pond area dries a bit more) is to lime the watershed area and throw additional lime in the water. I'm in an agricultural area and so that will be a fairly easy thing for me to try. Thanks for the suggestion!
Posted By: Dave Davidson1 Re: Calculating Gypsum Amount - 04/07/06 01:04 PM
Is there a breaking point on adding gypsum? In other words, can I overdo it? I expect I can.

I've never had muddy ponds before and am totally ignorant in this area. What should I be cautious about?
Posted By: bigfrog Re: Calculating Gypsum Amount - 04/07/06 09:20 PM
I've never heard of anyone adding too much gypsum. I believe that it does not significantly alter ph in most cases and so that is why some prefer it to Alum especially if they do not feel comfortable using Alum and then having to monitor ph and buffer if needed. The pond bosses here who are experienced with this I think would say that Alum is very effective, but that you have to be a bit more knowledgable and careful in its use. Using too much Alum can cause a big enough ph change to endanger your fish. So, I am not sure that you have to be all that cautious using too much gypsum...except to make sure that it is powdered and not pelletized. There is a warning post about using pelletized gypsum elsewhere in this section.

The second caution, if you can call it that, is that you have to use so much gypsum (In my case about 2500 lbs for a 1 acre pond.) Distributing it becomes an issue. Some people wash it out behind a prop in a stationary boat, some throw it out one scoop at a time by shovel, and some use a trash pump and pre-mix it with water and then spray it over their pond. Anyway that you do it, it can become a pretty good job.

Because there are several possible causes of muddy water, I think it is important to test your water in jars. If gypsum does not work well, then you have not wasted much time and energy and you can quickly change your strategy and try something else.

I am not an expert at all on muddy water either. Most of what I have written above came from others' posts here and a few papers I have read from a variety of conservation departments and other resources on the Internet. I will be interested in hearing how you solve your problem because I am still reading and experimenting to learn more so that I can improve my water clarity too.
Posted By: Dave Davidson1 Re: Calculating Gypsum Amount - 04/07/06 09:34 PM
Man oh man, that changes my weekend plan. I was going to try about 200 lbs. per acre to see what happened. I think I'll hold off awhile to see what happens.

I'm outa here heading to the country
Posted By: DWR353 Re: Calculating Gypsum Amount - 04/18/06 01:59 PM
I have a pond of about 1&1/3 ac in size 8ft deep. Upon suggestion of LSU extension office I put in 1600 lbs of powdered gypsum yesterday(17th). How long does it normally take to make a difference? We applied by pouring out of a bucket and bag into the prop wash of a trolling motor. It looks like it mixed very well using this method. We simply crossed the pond in a zig-zag fashion to spread out. Thanks.
Posted By: bigfrog Re: Calculating Gypsum Amount - 04/18/06 05:52 PM
If you have used enough gypsum, then you should see results fairly quickly. In my case, the results were dramatic within a week. I used a homemade secchi disk and my visibility went from under 6" to about 24" in that period of time.
Posted By: Dave Davidson1 Re: Calculating Gypsum Amount - 04/19/06 01:25 PM
I E-Mailed US Gypsum regarding where to buy Gypsum and how to use it to clear a muddy pond.

Here is the reply from Loren Miller of the Industrial Products Division.

Dave, please review our website @ gypsumsolutions.com, then click on distributors, then click on the state of Texas, then view the list of distributors that stock Industrial Ground Gypsum (coarse grind)-finer ground materials would not be as effective because it would dissolve too quickly-Also, you should use about 2,000 pounds per surface acre and you may need more than 1 application to do the job-you should apply the material on a day when the wind is blowing between 10 and 20 mph as this will stir up the water so that when you apply the gypsum it won't just sink to the bottom-Last, but not least you should also apply material to the soil or grassy slope that is leading to the pond as that is the area where the clay comes from during the rains.
Posted By: DWR353 Re: Calculating Gypsum Amount - 05/24/06 07:43 PM
Dave, using your info I put in 2800lbs in my pond. After one month visibility is now about 2 feet. Thanks for the help. This confirms that this is a great site filled with knowledgable and helpful people. Also, support and suscribe to the magazine, it is worth it.
Posted By: DWR353 Re: Calculating Gypsum Amount - 05/24/06 07:44 PM
Meant to say "subscribe", my bad.
Posted By: Makoclay Re: Calculating Gypsum Amount - 01/22/11 04:23 AM
Best thread on Gypsum I have found. Thanks to all who posted.

I plan to add some this spring to my pond. I am going to take a water sample and test the PH tomorrow and see what happens. I'll probably drop a few grains of sheetrock into the water to see if it makes a difference.

I just got a quote this week for the Gypsum. I was quoted $22.50 for a 50 pound bag. My pond is 1.3 surface acres with an average depth of around 7 feet. I figure 2,000 pounds should be more than enough but that is over $800 so we'll see. That is more money than I want to spend
Posted By: esshup Re: Calculating Gypsum Amount - 01/22/11 04:57 AM
Do they use any lime on the crop fields around there? If so, you should be able to beat that price by a long shot. Look for a co-op or farm fertilizer supplier in the phone book.
Posted By: Martin Brown Re: Calculating Gypsum Amount - 04/15/12 01:03 PM
That' seems too high. Gypsum is the same product that they line ball fields with. You can get at chemical houses for $8/bag. Don't know the weight but I would bet its 50 pounds.
Posted By: Rainman Re: Calculating Gypsum Amount - 04/15/12 01:11 PM
Martin, Hydrated Lime is also, maybe more commonly used to line ball fields also.

Hydrated lime runs around $8-$9 a bag at retail. Chemical distributors have to comply with very tight customer restrictions imposed on them by Homeland Security now, so it is not a matter of just going in and getting chemicals there at wholesale anymore.

FWIW, I have 4 major chemical distributors I use depending on where I am working...Hydrated Lime prices run from $.185 to $.445 per pound wholesale....all use Calcium Hydroxide made by Mississippi Lime Company.
Posted By: Impy22 Re: Calculating Gypsum Amount - 08/30/15 07:00 PM
From information found here, used gypsum in my sons 3 acre lake the results were fantastic, we have been fighting muddy water for three years found this forum and decided to try it we used a trash pump to disperse the gypsum and it worked great results were over night we tried hay last year without success so glad I stumbled on here and decided to give it a try. Thanks to all that have posted
Posted By: stickem' Re: Calculating Gypsum Amount - 08/30/15 11:12 PM
Originally Posted By: Impy22
From information found here, used gypsum in my sons 3 acre lake the results were fantastic, we have been fighting muddy water for three years found this forum and decided to try it we used a trash pump to disperse the gypsum and it worked great results were over night we tried hay last year without success so glad I stumbled on here and decided to give it a try. Thanks to all that have posted


Impy22,
Welcome to Pond Boss.......tons of good info and helpful folks here.....
Posted By: james holt Re: Calculating Gypsum Amount - 11/03/15 02:24 AM
I added a semi Truck load the first time I used Gypsum and now add about a fourth a truck load each year. I am assuming that Gypsum must have a residual effect since to have the same effect each year I add less. Will I eventually not add any?
Posted By: james holt Re: Calculating Gypsum Amount - 01/24/16 09:49 PM
Does it help to keep the alum or gypsum suspended in the water column off the bottom and letting it dissolve slowly in the water instead of sinking to the bottom? I think I remember eric west placing a bag of fertilizer on a platform in the water to let it dissolve slowly and not sink to the bottom.
Posted By: ewest Re: Calculating Gypsum Amount - 01/25/16 11:20 PM
Anything that will chemically bond with dirt (pond bottom)should be put on a platform /tarp/plastic bag etc if you want it to dissolve in the water rather than bond with the dirt.
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