HAMILTON, Ohio – The Butler Soil and Water Conservation District (SWCD) hosted a pond clinic at the farm of Nathan and Angie Gillespie. Nathan is the fourth generation of his family to farm the land. Their pond was dug in 1947 but has been cleaned out and enlarged. The clinic was geared toward anyone who owns a pond or is considering building one.

The presenters were Brady Smith, Butler SWCD rural specialist, who, among other things, talked about pond construction and aquatic weeds. Matthew Smith, The Ohio State University aquaculture specialist, addressed pond stocking and algae management with tilapia.

Ponds vary by type – excavated, embankment or a combination – according to the topography, Brady Smith said. Landowners with flat or nearly level land may choose an excavated pond. They’re generally ground water or spring fed. An excavated pond will cost more to dig than an embankment pond.

Building a dam between two hillsides creates an embankment pond. They’re more common on sloping land, where they collect and hold water from overland flow. Landowners may not build an embankment pond by damming permanent flow streams.

A combination pond is built by both digging and damming. They are the most common in type pond in southwestern Ohio.

Next, when deciding where to place a pond, Smith emphasized that the soil type must be suitable.

“When people call us and tell us where they want to locate a pond, I look at the USDA soil surveys to see if the soil is suitable for ponds and then the depth to bedrock,” Smith said. “In some areas we have shallow bedrock and that is not suitable for ponds; it would drain the water.”

While Butler SWCD cannot recommend a specific contractor, Smith suggested getting three competitive bids, having a written contract noting the work to be done, a time frame, the cost and conditions of payment, and if the contractor will seed and mulch the area.

Once the pond is dug and holding water, aquatic weeds are a common problem. There is a huge population of geese and ducks in the area.

“They will travel from pond to pond; many weed seeds are adapted to be transported by waterfowl,” Smith said. “The seeds will get caught within the feathers of the birds. When they land and hit the surface of the water, their feathers spread out and the seeds will disburse. Unfortunately, there is no good way to prevent that.”

Algae is big issue for pond owners, Smith said. It’s not necessarily from agricultural runoff but rather from people over-fertilizing their lawns. Maintaining a buffer around the pond which the landowner doesn’t fertilize is important.

The Smiths, who are not related, emphasized that when using chemicals for algae control, the label is the law – follow the directions.

Matthew Smith then talked about researchers investigating the use of tilapia for algae control. They are one of the few aquatic creatures that will eat algae.

“They are a popular species and are produced and farmed right here in Ohio,” he said.

The Gillespies have had success using tilapia to help control algae in their pond. Tilapia can’t survive below 40 degrees, so they stock them about the second or third week of May, when the water temperature is up, and scoop them out in the fall when it gets cold, Matthew Smith said.

Triploid Grass carp, also called white amur, are another fish option for controlling algae, although they are not a silver bullet, Matthew Smith explained.

Step one to a successful fishery is to have a well-designed pond. “If it is not well designed, if it is not built correctly, it is going to be hard to maintain a good fishery,” Matthew Smith said. “Check the size of your pond on Google maps to track how big it is. When stocking, the predator-to-prey ratio is one predator to five prey. For example, stock 100 bass to 500 blue gill.”

Finally, to check on how your fishery is doing. Matthew Smith suggested: “In spring, fish are spawning, you want to know whether or not they are spawning and if you’re getting good growth and good hatches. You can use a seine or fine mesh net and sweep the edges of the pond to see if you have baby fish, bass, blue gill, and so on. Another good way is keep a good record of what you’re catching. When people are fishing, just keep a notebook or note it on your phone.”