A concrete fountain is an outdoor investment exposed to constant water contact, freeze-thaw cycling, UV radiation, and biological growth. Without sealing, even high-quality concrete becomes porous over time, leading to leaks, staining, and surface erosion. The right sealer extends fountain life by years and can be applied by any competent DIYer. These five products represent the top options across different sealer types and use cases.
| Product | Best For | Rating |
|---|---|---|
| Aqua-Kure-Clear (Quikrete) | New fountain construction | 4.6/5 |
| RadonSeal Deep-Penetrating Sealer | Porous older fountains | 4.7/5 |
| ThoroSeal Crystalline Waterproofer | Full waterproof rebuild | 4.8/5 |
| SealBest Pro 30 Concrete Sealer | UV and weather protection | 4.5/5 |
| Pond Shield Epoxy Coating | Fish-safe permanent seal | 4.9/5 |
Aqua-Kure-Clear — Best for New Fountain Construction
Aqua-Kure-Clear is a curing and sealing compound applied to freshly placed concrete before the surface is fully hardened. It seals the surface immediately, locking in moisture for a better cure while simultaneously waterproofing the exterior. For new fountain builds, applying this during construction rather than as an afterthought produces better long-term results: the sealer becomes part of the cured surface rather than a coating on top of it. It is clear and does not alter the natural concrete appearance. Recoat every two to three years as regular maintenance.
RadonSeal Deep-Penetrating Concrete Sealer — Best for Porous Older Fountains
RadonSeal uses a siliconate chemistry that penetrates several inches into the concrete matrix and reacts with calcium hydroxide to form a waterproof crystalline barrier inside the slab — not just on the surface. This makes it ideal for older, weathered fountains where the surface layer has eroded or been previously sealed with incompatible products. There is nothing to peel, and the treatment is permanent for the depth it penetrates. Water beads off the treated surface, and the appearance changes only slightly to a slight sheen. One gallon covers approximately 200 to 400 square feet depending on concrete porosity.
ThoroSeal Crystalline Waterproofer — Best Full Waterproof Rebuild
When a fountain has multiple hairline cracks or significant water loss, applying ThoroSeal as a full crystalline waterproofing layer is the most thorough repair approach short of rebuilding. The brush-applied slurry penetrates and seals the concrete while bridging fine cracks. Its crystalline chemistry continues to self-seal minor new cracks that develop after application, as long as moisture is present to trigger crystal growth. For fountains with complex shapes or difficult-to-reach interior surfaces, ThoroSeal’s thick consistency and brush-on application gives complete coverage without pooling or running.
SealBest Pro 30 Concrete Sealer — Best UV and Weather Protection
SealBest Pro 30 is an acrylic-based sealer that forms a protective film over the concrete surface, shielding it from UV discoloration, rain erosion, and algae growth. It enhances the natural color of the concrete slightly, giving decorative fountains a richer, slightly wet look that many homeowners find attractive. The low-VOC formula is easy to apply with a roller or pump sprayer, and dries in about an hour. It is not rated for fish ponds but works well for purely decorative fountains, birdbaths, and tiered water features where water contact is minimal. Reapply every one to two years.
Pond Shield Epoxy Coating — Best Fish-Safe Permanent Seal
For fountains or ponds containing fish or aquatic plants, Pond Shield is the definitive product. It is a two-part epoxy coating that forms a smooth, non-porous surface rated food-safe and non-toxic for aquatic life once cured. The 45-mil thick coating completely encapsulates the concrete surface, eliminating porosity and the lime leaching that harms fish in newly cast ponds. It is highly resistant to UV, algae adhesion, and the chemicals used in water treatment. Cost is higher than other options, but the result is essentially a glass-smooth, leak-proof interior that should last a decade or more without recoating.
How to Choose a Concrete Fountain Sealer
Match the sealer type to the problem. New construction benefits from a curing sealer applied early. Old, porous fountains need a deep-penetrating siliconate product. Active leaks and crack patterns warrant a crystalline waterproofing layer. Decorative fountains with no aquatic life do well with acrylic sealers for UV and weather protection. Fish ponds demand a non-toxic, fully waterproof epoxy or certified pond-safe coating. Surface preparation is equally important — no sealer performs well over contaminated, wet, or flaking concrete. Clean and dry the surface thoroughly, then choose the sealer rated for your specific exposure conditions.
A properly sealed fountain requires far less maintenance and lasts much longer than an unsealed one. For related reading, see our best concrete for water features guide and our best concrete for underwater applications article. Our product evaluation standards are explained at /methodology.
Frequently asked questions
How often should I reseal a concrete fountain?+
Most penetrating sealers for concrete fountains last two to five years depending on weather exposure and water chemistry. Film-forming sealers may need reapplication every one to two years as the coating wears from UV exposure and water movement. Inspect the fountain annually for hairline cracks, white mineral deposits indicating water seepage, or surface deterioration, and reseal as needed before a minor issue becomes a major leak.
Do I need to empty the fountain before sealing it?+
Yes -- the concrete surface must be clean, dry, and free of algae, mineral deposits, and loose material before applying any sealer. Drain the fountain completely, scrub with a stiff brush and diluted white vinegar or a concrete cleaner, rinse thoroughly, and allow to dry for at least 24 to 48 hours before applying sealer. Applying to a damp or contaminated surface causes adhesion failure and premature peeling.