Known for its absorption and purification characteristics, Sheetrock can be a quick fix for a leaking or running pond. However, the chemicals and fibers used to construct Sheetrock can pose a detriment to a pond's dependents and initiate additional concerns. Before using Sheetrock to seal your pond, carefully weigh the pros and cons, as well as the alternative options.
Sheetrock is brand name for gypsum wallboard, which is also called drywall or plasterboard. Though the chemicals and additives vary by manufacturer, drywall is largely composed of hydrated calcium sulfate, known as gypsum. Gypsum, mined from the earth, is an extremely porous mineral with a naturally neutral pH balance. When saturated, the gypsum wallboard material can settle into place within the pond with little, if any, movement.
Placing Sheetrock in the pond is an effective way to seal its weak areas. However, pure gypsum is a more effective option. Unlike drywall, pure gypsum is void of chemicals and additives that are harmful to plants and wildlife. You can find gypsum in home improvement stores and nurseries in its pure form, and it is often less expensive than drywall.
Compacting the soil is an effective and inexpensive alternative to the drywall method. The compaction process simply involves filling the pond's holes and weak areas with clay soil and compressing the soil in place. Bentonite, granular-based clay, can also seal a pond when the pond's floor is free of water, moist and not saturated. Clay blankets, pond liners and dispersing agents offer additional sealant alternatives but can be more expensive than pure gypsum, drywall and the compacting options.
If you opt to use Sheetrock to seal your pond, try to position the drywall while the pond is mostly free of water. If the pond is completely dry, irrigate the pond lightly to create a moist but not saturated floor. Remove the paper that encases the drywall before setting it in place. Be sure that fish and wildlife, such as birds and cattle, do not drink from the pond, as the chemicals in the drywall will contaminate the water.