Pond Boss Forums GENERAL QUESTIONS Muddy water Clearing the pond with Alum

Ok, so refilling a 1-ish acre pond that was re-fed with well water that has high alkalinity and PH sitting around 9. Following some of the advice around here, I got Alum and using a trash pump and bribing a few friends/family with adult beverages we went to town.

Here we are before the start.





I estimated that we were working with 6-8 acre/feet and started with 750 lbs. The gallon test showed we would need more after the first dose (looking closer to 120-150 lbs per acre foot. But we went ahead anyways.

Had to do a second 350 lbs batch the following weekend and it took off.

Here we are after the second batch





If you are needing to clear a pond with Alum, keep going until it clears. It took two batches but the second one just made the difference. Also, PH dropped to a max of 8 during the afternoon after the treatments, so bonus effect.

Thanks to rainman and others for their recommendations,

John

It looks great!!

Is there any reason why one couldn't slowly add Alum over a month? Say a low dosage once a week, recheck numbers, and then repeat weekly until the desired clarity was reached.

Maybe the PITA factor in getting the pump, tank, etc (i.e. equipment) set up every week and then cleaned out again?

That's no issue, so I'll assume it's ok. I just didn't know if chemically it need to be done at all at once.

Thanks.

Al...Alum is only partially cumulative. It works as it falls through the water column and does not fully dissolve/disperse in water. "Partial Treatments" would only be good for new inflow, as and where it enters the BOW.

John, that looks great, can you retake the first two pictures so we can see the before and after looking across your pond?

Now I have to rethink alum again for Georgetopia, dang nabit.....

Brian, what did the jar test show?

If it was mine, I'd hit it, this time with enuf alum to clear the water, keeping an eye on pH.

What were the Secchi depths before and after?

I would advise you to take a gallon and adjust the PH with citric acid before you add to much more alum. I am betting that the clarity is coming more from a balanced PH. You could have a bunch of soluble alum that is not active because of PH and when it flips it will flip hard and fast on you.

I do not know what acid would be the cheapest or most safe for your fishies but I do know Chemistry.

Phosphates are very good acids for high PH for Potassium and Calcium and I am betting this is what is in your well water. If you could lay your hands on Calcium Carbonate this is the best buffer anyone can have for water. It will bring your PH up and it will bring it down as well to sit at a PH of 7.2

Cheers Don.

Sorry about the delay in response to some of the questions, work got crazy and I frankly didn't see the responses...

Bocomo--Secchi before was 3-4", after 18"

Brian, I will try. We had a decent rain and some evaporation so I have been adding water back in from the well. Currently I am trying to determine if what I am seeing it the water brown up again or just overfeeding on my part combined with 15-20 mph winds causing issues. But I am currently at about 9" vis. If I get a chance to get out when I can take a decent pic, I will. I also need to redo the jar test and see if it settles out.

John

Hey Don,

Just to follow up and make sure my non-chemistry mind is on the same page, are you saying to buffer the phosphates with Calcium carbonate when added or that the Calcium Carbonate will help bring PH down to 7.2.

I also understand that you are making no representation on impact to fish, more a question of how this would work. Since I live in an area where most of the impact on my pond is acidic, the basic component is the well water alone, it has a PH of right about 9. I am considering the idea of modifying my pump line to address the PH before it hits the pond so I am affecting a smaller amount of water and thus using less chemicals/minerals to do it.

Here is what we look like right now. It has gotten browner as we have lost water due to evaporation and I have pumped more in from the well.

First this is 10 days ago before I started the pump back up (black mass is catfish young)...


Here it is now with the pump running more well water into it and after a few good rainstorms that we got.




And here is a little friend who wanted to see what I was doing...(note: his head was the size of my fist)




Needless to say, I am currently doing another clarity test to see if it is darkened due to suspended clay or if it will settle out or if it is just a factor of too much nutrients in the pond water.

When I pull the water out and hold it in a jar, it is not as brown as it was before, but it is not clear.

We will see.

John

That school of YOY catfish. Have you taken one out to check to see if they are catfish or bullheads?

Yes. I got the pin pricks in my fingers to prove it. I netted a group and took it in for the kids to see, since I am happy to remove all catfish-young and old-at this point.

Edit: It occurred to me I wasnt very clear in my response. Best I can tell is that they were CC YoY. They had the forked tail that I would identify with CC. I didnt take any pictures of the ones I removed as I know I have a current batch of CC from last year that have spawned and survived.

John

Rentzlaw....unless you add enough flocculant (alum) to completely clear your water, future colloidal clay turbidity is almost guaranteed. The 18"-36" inches of "clarity" in a pond should be due to a planktonic algae bloom, and never from solids such as suspended clay.

The pond, almost overnight, turned a bright and brilliant green after the second addition of the Alum. What I was trying to determine from the recent color change was whether it was due to the charge of the new well water being pumped in to combat water loss due to evaporation or if it was simply water being stirred up due to water pumping, high winds (15-25 mph), dogs in the pond, etc.

I pulled some water out for a jar test and this is what I got.



This is 2 days old and there is some sediment that settled out. I will add a little alum mixture to see if there is some still there, but it looks like I just have some mechanical mixing going on. Atleast, that is my read from this.

I think it will clear more with more Alum, but let us know how the test goes!

Yes calcium carbonate is really the best product for your in feed water and it is very cheep. If your water has a high PH of 9 you will see it go down with calcium carbonate added.

You can find it at and ag story but you must make sure it is calcium carbonate not dolomite lime. BIG difference between the two.

Your high PH could be from the suspended cation exchange capacity of the suspended clay too. ITs just soluble to be tested by PH test strips.

Same thing as the alum grab a jar and drop in a pinch of calcium carbonate stir it up and watch what happens. Check PH with a hot tub strip too. You will see when the water flips it will all at once and it will look like snow flakes in it. Alum is very good at this but can take some time depending on how high your PH is. If it is up you may need four or five days to see any change. The alga bloom will tie up micronutrients as well and as the alga die or reproduce they will flocculate out too. This is where the muck on the bottom comes from.

Muddy waters with a high level of nutrients can be a hand full when water temps get up.

Cheers Don.

P.S. see if you can find calcite soft rock. I bet you could build a barrel that your well water can run through to help balance it before you add to your pond. See crayfish and some shrimp need calcium or a higher than neutral PH to live.

I did the same thing rentzclaw did with the same results. Clear water for a period of a couple of weeks and then muddy water again. I also pump well water into my pond. I think I am in the same area he is. His water looks the same color before and after and then after again.

same turtle and same catfish. wish I hadnt stocked the catfish.

46 cats removed this weekend. Knew having my dad come fish with his grandkids would be worth something...Now, to get the rest out...

James, I am thinking it will have to be a reoccurring treatment will our well water going in to keep it up. Rain would be nice...

I agree we need rain bad! Your pond looks identical to mine.

where did you get the alum?

I ended up over paying to have a local farm supply company in Denton order it for me. I am looking into getting it from the Estes company in Carrollton that I have heard people mention as a major supplier. My guy charged $40 for 50 lbs.