Pond Boss Forums INTRO Questions & Observations Water height

Small pond up north. About 3/4 acres. 7 to 9ft deep. Water is cloudy does have suspended particles. Tried some powder to clear up water few years back did not seem to help. Seems to be a lot of slime etc this spring. I have a 3 head aerator running. Pond is basically filled from the surrounding area no creek or spring. Lots of old farm land. When they dug the pond they had a water level overflow set about 4" below finished grade. Problem is see may be that I have about 8 to 10" of soil before hitting clay. Do you think that water level needs to be lowered below the topsoil??

It may be time to run some jar tests again to make sure you are addressing the correct problem.

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Jar Test - Pond Boss Thread

I will speculate just a bit for the three most likely possible causes.

1.) It might just be a bloom of phytoplankton. When the water warms and the sun gets higher in the sky, the tiny photosynthesizing organisms can exhibit a population explosion.

2.) It may be "suspended sediment". By suspended, I mean the water is physically agitated to keep the particles from settling. This can be due to rain eroding soil particles and transporting them to the pond. (Does it start clearing a few days after a big rain?)

This can also be due to creatures in the pond stirring up the sediments on the bottom. Some common culprits are goldfish, koi, carp, or bullheads. Sometimes it can even be channel catfish, crayfish, or even some of the less common species.

Finally, even waves lapping at the shoreline can keep sediment in suspense in shallow ponds. This is more likely when there are few plants or rocks on the shore and where the pond is in an open environment exposed to windy conditions.

3.) It may be electrically charged clay particles. If the clay particles are repelling each other, then they can stay suspended in the water column for a long time. Adding alum to the pond is one of the common solutions to this problem. (This may be the "powder" you added previously?)

What you are calling topsoil could be a problem due to either 2 or 3. I don't think lowering the water level will solve your problem, because any loose topsoil would tend to work down your slopes and collect in the deeper portions of your pond. I believe you will need to address the underlying problem.

I would try the jar tests, and come back with your results, and then you can probably get some feasible solutions from some of the pond experts.

I did the jar test. Sediment settled to the bottom. I added 100lbs of alum mix seemed to help a bit. Wondering if I did not use enough

IMO you definitely did not use enough alum for 3/4 ac of turbid water. Do you know the acre feet of water in the pond?? When you did the jar test did you do the math calculation of weight or amount of alum added to the jar for the volume of water tested?

When you add the alum, I would run the aeration until all the alum get well mixed into the entire pond volume, top to bottom. This may take 2-3 hrs after you finish adding all the alum. Then shut off the aerator so all the coagulated precipitate to settle to the bottom. This may take 4-10 days. Then restart aeration. Maybe slowly at first for the beginning 4-6 days. Watch for clarity changes after restarting aeration. Do you have a secchi disk and know how to use it?

Yes I do have a disk.thank you for your help!! Will let u know
results

IMO know the water total hardness / alkalinity before messing around with high doses of alum if fish are important. Hydrated lime may be needed with the alum when the pond has low or medium low and sometimes even a medium alkalinity concentration.

Jar Chemical test procedure.
1. Fill multiple identical jars with pond water.
2. Add a measured increment of flocculant (such as agricultural gypsum or alum) to each jar and stir thoroughly. For example:
1. Jar 1: 1 teaspoon of alum or gypsum
2. Jar 2: 1 teaspoon + 2 tablespoons of alum or gypsum
3. Jar 3: 1 teaspoon + 4 tablespoons of alum or gypsum
3. Wait 12-24 hours to see which mixture successfully clears the water and causes the clay to clump and settle at the bottom.
4. Calculate your pond's volume (length X width X average depth X 27,154 gallons per acre-foot) and scale up the dosage from the most successful jar's water volume to treat the whole pond.
Bob Lusk says this
https://www.pondboss.com/news/inside-pond-boss/clearing-muddy-water
If the pond has low alkalinity(hardness) then the alum does need to be buffered with hydrated lime so the water does not become too acidic and kills fish. See Bob Lusk’s info above.

Rainman on the Alum Kicks Clay Butt says this: For about 1.3 ace/ft of water, I'd suggest 100 pounds of alum and 50 pounds of hydrated lime. If it doesn't clear in 24 hours, add 50 more pounds of alum, Hy Lime could be optional on the 2nd application..
A 3/4 ac pond likely has more water in it than 1.3 ac ft of water!!! Amount of suspended clay in the water also affects the amount of alum needed to make the water clear. IMPORTANT NOTE -- if the alum treatment does not make the water clear the turbidity was probably not caused by suspended clay.
See this thread for other options of cloudy water.
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=37851