Epoxy Sealer Paint
Look for an epoxy sealer paint specifically for cement ponds. Epoxy is derived from petroleum products with a high level of bonding properties. It offers a hard layer of protection and is resistant to humidity, moisture, excessive heat and low temperatures. The epoxy is waterproof and will seal the concrete walls of a fish pond.
Choose Low or No VOC Epoxy Paint
Volatile organic compounds (VOC) are hazardous gases emitted from a variety of common products including epoxy paints. Purchase the paint from a location that specializes in fish-safe products. Hardware and home improvements centers have a wide variety of epoxy paints. Call a local store to ask if it carries the appropriate product for your needs or if you can order it through the store. Local landscaping companies who install fish ponds will also be a good source of information about choosing the right paint with low or no VOC. Read the paint labels carefully to check that it is safe for fish.
Before You Paint
Clean the concrete pond to assure proper application. Vacuum the pond with wet/dry shop vac. Scrub the concrete surface with a wire brush and warm water. Use a garden hose to rinse the area completely.
Painting the Pond
Once you have sufficiently cleaned the concrete surface, check for cracks. Patch the cracks before you apply the epoxy paint. Concrete patching compound is available at hardware stores and home improvement centers. If you have patched cracks, those areas must be dry before painting. Read the directions on the paint can and follow them exactly. Wear protective gloves and a breathing mask. Use a paint brush for application, and let the first coat dry before applying the next coat.