Tannic Acid in Ponds

If you’ve ever driven by a lake that has brown water resembling ice tea then you’ve seen a pond with tannic acid.  Most of the time tannic acid is just an aesthetic issue. However, sometimes it can be more serious. This client was about to stock 6,000 3-4″ bluegill before we checked his water quality. The water didn’t even hold 1 milligram worth of oxygen. This would have been a death sentence for the bluegill and an ill-spent $3,600.  To help reduce the tannins in the water and improve oxygen levels we applied aglime. Aglime contains high amounts of calcium which raises the pH levels and alkalinity.

Checking oxygen levels
Josh is checking the oxygen levels of the pond.
oxygen levels
Oxygen levels are still substandard. The percent saturation is about 15% at 1.21 milligrams per liter. Ideally we want the percent saturation around 100% and milligrams per liter at 6-8.
Duck Weed
In addition to high levels of tannins the pond also has a severe case of duck weed.
Boat ramps are great but we can always bob sled down a gentle red clay bank if need be .
Tractor loading barge
Getting loaded up with some aglime.
Loading lime
Keeping the barge still and dumping the load is a dance. Luckily there was no wind today to cause the boat to drift.
Dump truck
We weren’t the only ones dumping today. This is a new pond so getting rock and gravel dropped is key to keeping the dam healthy.
Lime barge
We nosed up into the brush as much as possible. These decomposing organics are what are causing the high levels of tannins.

With the aglime applied we will give it a few months to start changing the soil and water characteristics. Although this is not a good situation  it could have been much worse if fish were stocked. The owner isn’t on the property at all times so the fish would appear to go in healthy but by the time he was out next the buzzards would have cleaned everything up. If you ever face a tough situation with your fishery give AES a call. We have plenty of experience and creativity to solve problems.