Pond Boss Forums Thread Like Summary - SE OH: poor clarity, is bloom healthy plankton?

I would like your input about the appearance and health of my pond.

Please excuse my clumsiness and repeat posts. I am trying to learn how and where to post threads, and I am still trying to learn how to post photos.

My 22 year old SE Ohio clay bottom pond still appears muddy with poor clarity after removing fish to reduce the potential for clay disturbance, adding aeration and bacteria, administering 1600 lbs ag. Lime, 24 gal aluminum sulfate and hydrated lime (details below).

The clarity improved from 5" to 12-15" per secchi disk readings.

5/29/23 615 PM
Secchi 12", pH 7.6, Total Alkalinity 60-70 ppm, Calcium Hardness 60 ppm, TDS 89, EC 178, T 70.5 f, and No phosphate, nitrate, ammonia per titration.
Two gallon sample jars: one placed in in-direct light, one covered with dark towel.

5/30/23 815 AM
Secchi 12", pH 7.4, Total Alkalinity 70, TDS 83, EC 166, T 66.3

The LMB, BG and other wildlife appear healthy. The increased light appears to have triggered a brown phytoplankton bloom with zooplankton moving around in the water. There is no unpleasant aroma.

Here is a brief review:
The pond was built in 2001 on a ridge top in SE Ohio with heavy clay soil and a perched water table. It is seep/spring fed and a small forested watershed, mostly oaks. The edges of the pond are well covered with native plants.

It is 0.75 acre ft with 488,000 gal (11 ft center depth, avg 4 ft depth). It can also be said that it is 0.202 surface acre or about 1/5th acre.

The pond developed poor clarity a few years ago; sometimes a deep coffee with cream color, Secchi 5".

I invested in various water testing gear and kept records; nothing stood out as being out of the normal levels.

Numerous Jar tests: Very little clay / sediment / other settled out in in-direct light and/or darkness during >24 hour periods.

Experiments with alum, gypsum, lime, epsom salts revealed colloidal clay issues.
Alum was most effective so we continued our testing to determine minimal needed dose, along with h. lime to keep pH in safe zone.

I removed possible causes of mechanical clay disturbance. It did not improve the clarity, reduce the turbidity but I wanted to reduce the potential for anything to kick up floc after an Alum treatment.

June 2019 Bowfishers removed a very large grass carp: 4 ft long, 53 lbs.

June 2022 aeration added for the first time when the off-grid solar electricity system was enlarged: linear diaphragm pump with a diffuser membrane.
(I chose this type of pump due to my limited supply of off-grid electricity. It is positioned upright on crates approx 7 ft from the bottom to reduce back pressure and extend the life of the pump. I know that it is less than ideal but it appears to be de-stratifying the pond based upon even temperature readings. I have not seen any adverse effects, unintended consequences.)

July 2022 I added “go clear” and “muck stopper” aerobic bacteria.

Aug. 2022 I removed two large channel catfish. (There is still one in the pond as of May 2023.)

Sept. 2022 I added 800 lb agricultural Lime (calcium carbonate).
April 2023 I added another 800 lb ag lime.

May, 2023 I sprayed 12 gallons of liquid aluminum sulfate onto the surface of the pond, with increased amounts in the deeper areas. The alum was applied in sections with close monitoring of the pH and the hydrated dolomitic lime (calcium magnesium hydroxide) was distributed in swaths to keep the pH close to neutral, and provide fish, etc., escape paths.

The chemistry remained good and the secchi disk measurements improved with clarity going from 5" to 12-15" but the goal was 18" clarity.

I was told to add another alum/h. lime treatment if the first did not work. I administered another 12 gallons of alum and hydrated lime without improvement.

But, I was later told that the aluminum sulfate / hydrated lime treatment needs to be administered in one full dose, approximately 200 lb / acre foot.

So, I am back at the drawing board.

Thank you.

[img]https://share.icloud.com/photos/044e2NAO1veWh7zBHrmr647Ew[/img]

[img]https://share.icloud.com/photos/044e2NAO1veWh7zBHrmr647Ew[/img]

I once caught a BGxRES that was very dark on one side and very light, like the bass you showed, on the other. On close examination, it was missing one eye. I hypothesized that visual cues directed the chromataphores coloring the fish.

Post the photos to Imgur, then you can link to them here and they will show up.

I would try Gypsum. Here Gypsum is about $160 per ton and that should be more than enough to clear up a pond that size. Gypsum doesn't work as well as Alum, but Alum here is $50 per 50lb bag. Plus with Gypsum, you don't have to monitor PH levels. To apply gypsum, I just throw a handful at a time into the prop wash of my electric 5 hp motor, it dissolves instantly.

What is the longest time that you let your pond water set in a gallon jug to watch for settling of solids?

I would stake my reputation that your pond is not predominated by a diatom bloom. Algae / phytoplankton blooms come and go (wax and wane) due to nutrient variability and fluctuations; yours appear to be a persistent problem. Brown hue algae blooms normally do not have the color of your pond. Your color has a mud -dirt color. I can microscopically look at your water and verify the type of particulates. My guess at this point is detritus, silt, and clay is the main cause. Your current problem is not an algae scum type of problem that is referred to in the Kentucky booklet you reference above. You do not have a scum. You have particulates that are present in the entire water column, top to bottom,

What would be the cause of the history of pond only developing the problem a few years ago? I wouldn't think the soil is much different than before. It might be good to explore this line of thought. Early on, was there a treatment that affected water chemistry? One thought, maybe it lost its earlier alkalinity over the years and the recent liming will help ... given time. Another thought, maybe mechanical disturbance is worse than thought, eg maybe other species that OP isn't aware of? Yet this wouldn't explain two weeks and a jar not settling.

Anyways, good luck and keep us posted about progress.