Learn how to clear murky pond water with silt or clay runoff and consider adding a small pond where water can collect before entering the main pond.
My home is serviced with water from a pond. It goes through a few filtration and chemical steps before getting to the faucets. I have a windmill for an aerator. When we get high winds or heavy rain, the water won’t clear for days, even though I backwash the system several times and drain the holding tank. Do you have any suggestions, short of dredging the pond?
Your response will depend on whether the matter is silt or clay particles or an algae bloom, as well as on the size and depth of your pond.
Heavy rains can wash in clay or silt. Does a stream or ditch feed your pond? If not, is there an area around the pond where rainwater concentrates before running into the pond? If any such areas aren’t grass-covered, or if there are one or more focused points where the water rushes in, that could be a source of the silt or clay entry.
If you find such a source, consider adding a small pond where the water can collect before entering the main pond; this way, heavier sediments can fall out before entering the main pond. Yes, heavy storms will end up allowing finer sediments into the pond, but an additional small pond could keep the larger debris out. Once the small pond fills with sediment, it’ll be less expensive to clean than the main pond would be.
If your pond is at a low level and the banks of the pond are exposed to waves, there could be some erosion happening. Additionally, in high wind and rain, the incoming water could be carrying sediments. Once in the pond, the diffuser from the windmill will help distribute the sediments to more of the pond. If this is the case and you know a rainstorm is coming, you can turn off or bypass air going to the diffuser until everything settles down in the pond. This should work even if high winds are forecasted.
Another option is raising the diffuser off the bottom of the pond. While I don’t know the brand of your windmill, I know of two different styles of diffusers. The first is an open diffuser, which would simply sit on the bottom of the pond. The second diffuser type would be sitting in a 5-gallon weighted bucket sunk to the bottom. If you’re using the bucket, that shouldn’t be an issue unless it tips over, but the open diffuser may be too close to the bottom. When the wind picks up, it could be stirring up the silt, muck, and sludge on the bottom of the pond. To address this, raise the diffuser from the bottom. Maybe start with the height of a milk crate.
If you’re looking at a possible algae bloom from the incoming nutrients or from stirring up silt, muck, and sludge from the bottom, this would entail needing to know your pond size and depth to calculate treatments and their dosage. Your options could include looking at phosphate inactivation, which would help lock the phosphate so the algae can’t be used as a food source. Other treatment possibilities are copper sulfate or a peroxide treatment, which have been used in water-treatment plants. Additionally, your ability to have an herbicide shipped in will depend on where you live.
