My 5 yr old pond has had suspended clay problems from day one. No runoff; rain or wellwater only, chemistry great with pH of 8.2 or slightly higher. I cleared it the first 2 years by starting a bloom. Now I have FA and chara and I don't want to feed that stuff so I tried aluminum sulfate. Visibility is about 6", not enough to start a natural bloom. Winter weather kept things churned up this year.
I did the 5g bucket test. 1 acre pond average depth 5 feet, I cleared the bucket with about 0.4 grams and pH dropped to 7.6. I couldn't find a definition of Moderate or Severe turbidity so I used the TAMU chart and decided on 150 lbs, just to be safe. I just want enough clearing to get a bloom, then it takes care of itself.
I sprayed the 150 pounds over the pond, aerator off. The milky streaks lasted about 15 minutes, no evidence of floc. Waited 3 days, nothing different. pH is still 8.2
Questions: Have I lost the alum I applied? Should I start over? If not, what increments should I apply additional alum in so as not cause a pH crash? How long after you apply can you take a valid pH reading? I apologize in advance if I have offended our moderator(s) by starting a new thread on this already lengthy topic.

Your pH is high enough that you shouldn't have to worry. In fact, if your pond is near full, it may begin to clear as the water level drops.

Great questions - I am looking forward to the responses.

DKFarms, I've never cleared a pond with less than 50 lbs of alum per acre foot. You'll have a maybe a slight residual amount, but I assure you some flocculation occured and the alum is now on the ponds bottom locked up.

I would suggest 400 pounds alum and 200 lbs Hydrated lime. Trying to "Partially" clear the pond is not a good idea as you want to establish water that is positively charge rather than neutral or new particles entering will easily suspend again.

Remember to spray amounts in relation to depth, ie 50 gallons over 10 foot depth versus 5 gallons over 1 foot depth.

Thanks for the suggestions. Is it safe to assume that every time you add alum there will be some flocking and all the alum will be bound up, even if there is no apparent clearing? If that's the case, could one add alum, providing there is no additional clay input, in increments to clear the water gradually? That's the way it looked like it was working when I did the 5g bucket test. I know you said it's best to clear it up and build up a positive charge in the water, but today I saw the first signs of Chara and when the sunlight hits that stuff, it goes crazy. I put a little herbicide on it in places to keep it from overgrowing during the summer but still maintaining some vegetation for the smaller fish. After the bloom starts in my pond, it clears up nicely, 18" to 24", and stays that way till winter. I just need to clear enough to get the bloom going and to get the fish biting again. I'll go order some more alum Monday. Thanks again for the input, I truly appreciate it. One day maybe I'll be smart enough to give somebody else some advice on this pond stuff.

DK, I'm not positive what will happen with the Chara, but the alum binds up and removes all the phosphorus in the water so the plants can not use it to grow.

I tried the TAMU test again with 5 gallon buckets. And again, the test results, according to the chart, say 150 to 200 lbs. I bought another 200 lbs to apply. I'll get to it sometime in the next couple weeks in between last soybean plantings and first hay cuttings. I know I need to do something quick because my LMB are super skinny I assume from not being able to see things to eat. The rogue Bream are full of eggs but should have spawned already. Don't know if the turbidity has something to do with that or not. I'll keep ya'll posted.

Keep in mind that the bucket test is the MINIMUN amount to use. I'd go with 3-400 lbs.

Here's my experience. The bottle tests showed I needed approx a ton of gypsum to clear up my very turbid 1.8 acre pond (2-3 " visibility). I added over 2 tons this spring (over about 6 weeks) with very little to show for it. We had heavy rains over the course of the spring which certainly didn't help me. I talked it over with Clint at Overton and he told me it might take as much as 8 tons. I was putting the gypsum in 1 shovel full at a time in my trolling motor propowash and it was the expensive powedered variety ($10 for a 40# bag but more surface area should be better) so I was pretty discouraged.

The rain slowed way down. I was adding a couple bags of gypsum a day after work and suddenly the pond started to clear. Over the course of a week I went from 4" to 22" of visibility. I also note that there is a similar sized pond downstream of mine that catches the overflow off my pond. That pond cleared first and has 30+" of visibility now. I have fertilized my pond and I am trying to keep it at about 18" of visibility.

One other note. If your LMB are feed trained they will eat even in muddy water. It's not as good as them being able to see their prey but it's probably better than nothing.

I have noticed the LMB are getting much, much fatter and beating the CC to the feed since the water cleared. I hav elots of BG, GSF, and a handful of tilapia as well.

Soft rain water, especially directly from the sky, is the worst for keeping clay in suspension. I wasted a bunch of alum and hydrated lime. I would add it, the water would clear, then the rain would wash my nice treated water over the dam. I gave up until my pond is down 1.5-2', but that may never happen here.

LMB can catch prey on moonless nights in murky water, so the muddy water is probably not the only reason they're skinny.

bobad,

Is there a difference in long term abiity of different coagulants to help keep a turbid pond clear? I am under the possibly false impression that gypsum lays on the bottom and helps control the suspended clay going forward. I'm not saying excess gypsum laying on the bottom will keep the pond clear, just that it adds some concentration of positively charged particles to the mix and will help you control the suspended clay with less addition required going forward than the original application. Perhaps it's just wishful thinking.

Not sure if alum works similarly or not although I suspect it does, I was too afraid of the pH swings to try alum.

halfastro, You know I've been wondering the same thing. It's a great question! I've been told that clearing ponds in area's that have say a lot of red clay is only a temporary remedy. That it will have to be repeated every year or so no matter how much grassy shoreline you have and even though there is not a large amount of clayee run-off going in your pond. Maybe someone here has had lots of experience with different ponds to give us some good info on what to expect...du

Update. Finally got around to putting another 200 lbs. of aluminum sulfate in the pond 2 days ago. Visibility went from 6 inches to 24 inches in about 10 hours and seems to be holding there. The pH started off at 8.2 and barely dropped to 8 when I checked today. The pond has that familiar green color again and I saw one of my skinny bass jump out of the water to try and catch a dragonfly this evening, so it must be getting easier for them to see. Response to feeding seems slightly better or maybe I'm wishful thinking. I turned the aerators back on tonight and started the water well since the pond is about 6 inches low. We'll see if either of those activities mucks up the water again. I'll update later this week. I'm going to buy my bass 5 pounds of fathead minnows for a treat.

Sorry I missed your post.

I don't think it matters which chemical is used as long as you use sufficient quantities. (And watch your pH)

Spreading an insufficient amount of chemicals can clear up water instantly but temporary. When a sufficient amount of chemicals are dissolved in the water, it will permanently clear it up. Permanently that is, until you get a lot of rain and lose your expensive treated water over the dam.

Alum is the easiest to dissolve of the common remedies. You can pour a pile of it in a corner of the pond, and it can be detected in the far corner 1000 feet away within an hour or 2. Gypsum dissolves more slowly, and needs spreading.

I've seen ponds that have such a high chemical load that you can stir up mud on the bottom, and watch it settle perfectly clear before your eyes. Water like that is usually the result of evaporation during a long dry spell, which concentrates the chemical load.

Update. The pond seems to be holding at 18 to 19 inches visibility with a 6" secchi disk. Aerators are now running 24/7 again. Fish activity seems to be picking up at the feed ring. I can see a few bass stalking the edge of the pond now. I threw in 2 sacks of crawfish for them to feast on yesterday. The greenish color sure is a whole lot more pleasing to look at than the milky white it had turned. I'll wait another week to see if the bloom gets better and maybe I'll fertilize a little. pH is still 8.0 or thereabouts.

Bobad, in your last post, did I understand you to infer that you put alum in a pile in your pond? Does that work? It would sure beat the heck out of the gyrations I have to go through to get the stuff sprayed on the water.

dkfarms. It sounds like you got some phytoplankton forming with the greensih color; that is good. Not sure about what bobad means but alum piled up is very insufficeint the more you have in solution the better you have a chacne to "grab" suspended charged particle and floc it out. Makes me nervous you might have a fish kill later if some left around on pond bottom.

Yes.

I dumped it into a pile in a shallow corner of my pond (where there are no fish), and it dissolved within an hour or 2. Flocculation occurred all over the pond. Unlike gypsum, alum dissolves exactly like salt or sugar. If your pond has suspended negatively charged clay particles, the positively charged alum diffuses chemically. Remember your chemistry lesson where a drop of skunk odor permeates a large room within 10 seconds? Alum works the same way. You couldn't stop it from diffusing quickly if you tried, assuming the water is not already saturated with chemicals. Try it in a wide pan of muddy water. A pinch of alum in one corner will settle the clay in the entire pan.

The only advantage I know to spreading alum vs. dumping it is that it works quicker. Spreading it, it takes 2 minutes. Dumping it, it takes 2 hours.

bobad now you got me thinking this is far easier than mixing it in solution. I will have to do some research b/c your method is very different than all recommendations. I'm not worried about time it takes just clearing the pond. Also how do you add hydrated lime if it works slowly?

bobad, I know your method is working for you but for the life of me it sure defies all the science of Alum's chemical properties and actions.

Bobad,

I am tried your method in a pond today and will let everyone know the results tomorrow.

With all my supplies sitting in the garage waiting to be applied, I'm also very interested.
I do agree with Rainman, it seems to defy logic. How it could dissapate effectively/evenly accross that much surface area. Doesn't exactly work on the same principals of pouring in a gallon of pond dye.


Jeff-

Actually, it does.

Works the same way as dissolving salt, sugar, or alum. The particles are much larger in dye, but they are held in suspension by their molecular charge.

You can put a spoon of salt in 1 end of a long, skinny pan of water, and it soon dissolves. The entire pan of water will very soon be equally salty. You couldn't stop the process if you tried. In all fairness, stirring the pan of water will cause the salt to thoroughly dissolve in a minute instead of an hour if you're in a hurry.

Getting a little technical, molecular diffusion and Fick's law are the reason salt, sugar, and alum dissolve so readily.

Soluble substances quickly diffuse from highest level of concentration to the lowest. Substances with a positive charge quickly diffuse, and balance the charge equally. Nature abhors an ionic imbalance. That's why a pond is either 100% muddy or 100% clear.

I think some of the confusion started because of ag lime, which dissolves so slowly it needs to be spread. Gypsum also dissolves slowly, and can benefit from spreading. Alum, like salt and sugar, is hygroscopic, meaning that it readily dissolves.

Thanks for the breakdown. I was under the mistaken impression it simply attracted clay to itself as it sank. I didn't realize it disssolved in the water.
Good thing you guys aren't prejudiced against dumb rednecks.

Jeff-

Didn't work for me.

We already added 100 lbs. a couple of weeks ago but wanted to clear it up some more. Visibility right now is 12-18".

bobad,
Thanks for explaining but does it not bind to clay particles lying on the pond bottom? The reason we apply ag lime across the whole entire pond to get it to fall on as much bottom clay as possible to then change soil chemistry so then water chemistry is improved. I know for a fact applying lime in only a few places in the pond does little to help the water vs. applying properly. I'm still not convinced alum is not needed to be diluuted in the water column to capture suspended clay either slow or fast.

Is it possible for the alum to bind to bottom clay or simply not have enough charge to be "pulled" into the water to bind with suspended clay????

And again I'm back to the PH part of adding alum if acting slowly if you will how do you balance the pH with hydrated lime? Thanks for your time.

DKFarms, where did you purchase your aluminum sulfate? Looking for lime also, can you help me out!!

Thanks

Howdy, Q2, and welcome to the Forum!

Greg,

The alum will bind a little, but the bottom mud can't contain a higher alum concentration than the pond water. That would break Fick's law, which states that molecules quickly travel from areas of highest concentration to areas of lowest concentration until balanced.

I've noticed that pre-dissolving and spreading the alum can quickly settle suspended clay, temporarily clearing the water. It looks very impressive. However, as wind and fish stir up more fine clay particles, it will once again go into suspension. If the water has a high enough concentration of alum (in combination with other positively charged chemicals), you can stir up clay all you want to, and it will soon re-settle. Most pond water (especially in old ponds) has enough calcium, magnesium, salt, etc. that it doesn't take a lot of alum to settle it.

Some ponds are almost pure rain water, and it takes a lot of chemicals to saturate it enough to occupy the negative ions.
That's why a dosage of alum that clears up 1 pond often doesn't clear up another.

Well, the pond is back to 10-12 inches of visibility again. The rain has clouded it up some. My bass are still skinny but the bream seem to be alot more active and willing to bite lately. I put a floodlight near the water's surface to attract bugs as per one expert's recommendation. The turtles and my duck sent me a thank you note with a bouquet of flowers and a bottle of wine. After a week or so I started to see some bass come to the light for bugs. Strangely, I do not see any minnows of any kind anywhere anymore, even under the light. The bass have eaten everything I suppose. My hatchery guru says I should put some pea gravel pads in the pond for the bream to spawn on. Without that, he says the eggs won't make it on the clay bottom and the bass food supply will dwindle even more. The bass will eat the fish food, thankfully.

Thanks to all of the great input from the group, I know what I need to clear the water. My 2 applications of aluminum sulfate worked to some extent. Now I just need to get saturation like Bobad advocates. I may even try his method; I'll put a bag at 8 or 10 locations around the pond perimeter and see what that does. It is such a pain to jump the through the hoops to get that stuff prepped and sprayed. QuickII, I bought my AS from Hanks Warehouse in Rayne,LA. They can order it in 50 lb. bags for about $20 a bag. It's granular so it takes a little stirring to get it dissolved.
Thanks again for letting me start this thread and taking the time to guide me in the right direction.
Ken
DK Farms of Roberts Cove

The best results in life are rarely easy.

This has been a great read. So answer me this, my pond is 3/4 full and its about 1/2 acre average 4ft deepest 8ft, if i put 3 50lb bags of alum in there and it clears up to a decent clarity then the rains come and the water runs off the pasture and down the clay banks its going to get muddy again but the alum will still be in there on the bottom, right? Then when its full I can do it again and and again untill it stays clear and al that alum will stay in my pond. So from then on out every time it gets disturbed from the bottom some alum will be kicked up along with the clay and it will settle back out.Also could you explain to me about the difference in ponds that are mainly filled with "soft rain water" my pond is mostly rain water I dont have much water shed. I know that if I do this now I will need to do it again when full. I just dont know if I should wait or start doing it now. some pics here http://public.fotki.com/tz/clearing-and-pond-p/34-full/

tz666,

I'd suggest planting some rye or other grass to reduce erosion. I doubt 150 pounds of alum will make a noticable improvement. You will most likely need 400-500 pounds. Unless over-treated, I've seen no evidence that alum is cummulative in the water. I have had several people tell me that they added multiple "less-than-needed" applications (all with little or no clearing happening) that totaled more than the originally required application would have been. Once the larger applications were made, clearing occured.

Ok from what I am reading I can take alum, I have a john boat to the deep area of my 3.5 acre pond and dump it to do the job? Question is, what is the ratio of alum to water volume?
Average depth is 8ft after this Texas drought is over.....

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=124005#Post124005
3 1/2 acres.. I would suggest reading this thread for info on determining if alum will help, how much to use, and the methods for applying the chemical..du

10 pounds water to 1 pound alum works very well. Or 55 gallons per bag. I mix 50 pounds to 35 gallons in my sprayer, but it takes longer to dissolve well enough to apply.

A pond is truly an interesting phenomenon. My turbid pond with 6 inches visibility, has over the past 45 days, cleared to a spectacular 34 inches, measured by secchi disk. No change in chemistry, tests are the same as they have been all summer. Only measurable change is temperature, average temp at 12 inches has dropped from 85 degrees to 80.5 since August 7th. Chara is thriving as it does every year with cooler water. So what happened? Did those multiple applications of Alum finally "kick in"? I'm as bumfuzzled as ever now, but it's a relief to see that the bass and bream have actually spawned. One day I'll figure this stuff out; maybe.

If you do, PLEASE share it with us!

Does the well water he is adding have a negative effect on clearing the pond if the well water is soft just like the rain water? How can you increase the number of pond plants on the bottom of the pond in order to decrease wind erosion?

I was hoping rainman would chime in by now. I know you are busy but what are your thoughts/

The Alum will not just suddenly "kick in" and I can assure you if the turbidity was from colloidal clay, there was certainly a chemistry change that had just never been measured. Unless your Ph was below 5.4 (which it isn't) the alum will not dissolve in the water and would have eventually settled out of the water column and was bound up in the sediments. With the little information we have on your pond, I wouldn't even venture a guess as to what caused the sudden clearing of your water...it's a stone cold mystery to me.

Intense growth of Chara and or other pond plants can have a clearing affect on the water. Abundant underwater plant growth including filamentous algae can cause clay particles to settle; possibly due to some resultant activity from photosynthesis.