Concrete is a great pond building material as well as the bricks. But both type of pond needs to be waterproofed before you stock it with fish. It can be done by using liner, paint or other sealants.
In this article, I will talk about two best pond sealer and paint that you can use to waterproof your Koi pond.
Our Recommended Pond Sealer And Paint
What Type of Paint or Sealer is Used for Waterproofing Pond
Although there are many ways to seal a pond, Epoxy paint and Liquid Rubber paint is most widely used. You can also use other waterbased waterproofing paint for this purpose. But these two work best.
Epoxy paint is the first choice of pond owners and there are good reasons behind that. It consists of a base as a curing agent. After you have finished painting your concrete pond, it will give a durable waterproof surface.
The reason is Epoxy is resistant to chemical agents which makes it last longer. Another good side of Epoxy Paint is it is fully safe for fish, pond plants and any other animal.
Epoxy paint is brittle. Hence if the concrete has micro-crack and any settlement occurs after the painting is done, it will break in that place.
The downside of epoxy is it is expensive than other paints. But being nontoxic it is still the first choice when it comes to painting a concrete pond.
As a substitute to Epoxy Paint, you can use the Liquid Rubber paint. It is cheaper than Epoxy and can give almost the same performance.
After application when it is cured, it forms a waterproof membrane. Being flexible it will not damage easily. Also, rubber paint doesn’t contain any volatile material and non-toxic to fish and another animal. You can use this one when you want to save some bucks.
Best Pond Paint: Pond Armor SKU-BLACK-QT-R Non-Toxic Pond Shield Epoxy Paint
The Pond Armor SKU-BLACK-QT-R (link to amazon) is the best epoxy pond paint widely used for sealing concrete ponds. It works on various type of surfaces like brick, stone, and concrete.
The best thing about this pond paint is it doesn’t require any primer like rubber paint and it only requires 24 hours to cure. It gives a very smooth surface. Therefore, there will be fewer algae growth in it and cleaning is very easy.
Also, Pond Shield made this Epoxy paint flexible, not brittle. Hence, it will not crack with the concrete and hold water well.
It is safe for fish, plant, and other animals. You can also use it for a turtle pond and birdbath. It also has a great temperature resistant. It can prevent the freeze and thaw action due to temperature change and hence lasts longer.
The coverage of this epoxy paint is awesome. The pack of 1.5 quarts will cover 60 square foot in one coat. It is available in 8 different colors.
Best Pond Sealer: Liquid Rubber Waterproof Sealant
Liquid Rubber Waterproof Sealant (link to amazon) is the best concrete pond sealer. It is a water-based liquid rubber sealant that is safe for both fish and the environment. It is free from any solvent and also VOC free. It works on various type of surface and concrete.
After application, it will form a membrane that is fully waterproof and gives a pleasing appearance. In the bottom, you should apply 3-4 coat in the bottom and 2-3 coat at the side.
The coverage of this sealant is good. It gives 50 square feet per gallon for the flat surface and 100 square feet per gallon for the vertical surface. Use paintbrush or roller to apply this sealant. Use 2 coat of primer before you apply this one.
This liquid rubber sealant should be applied is a completely dry condition. The surface should be free from dust, grease, oil, and paint. While applying the surface temperature shouldn’t be less than 5-degree Celcius.
It will take one to two days to cure. And after that, it will fully hold the water in your pond.
Why You Should Seal Or Paint Your Concrete Pond
The first reason why we paint or seal our concrete pond is to stop lime leaching. Concrete contains a large amount of lime. Not all the lime is used when the concrete sets because it is a never-ending process. The hydration and setting of concrete go forever. If you add water to a newly constructed concrete pond, you will see thing layer of lime over it after 24 hours.
Now, these extra lime can leach and mix with pond water. Lime in water is harmful to fish. So to stop lime leaching, we should seal the concrete pond.
Another reason to seal a concrete pond is to save the reinforcement that is within the concrete. If the concrete is highly damp with water, the reinforcement will get corrosion soo. The result will be a large crack in the pond and water loss.
Although concrete can resist water to some degree, if there is a constant water load on concrete, the water can percolate through it. This causes water loss in the pond and also makes the outside of pond damp. And if the pond is above the ground, there will surely be algae and moss growth which will make it unpleasing.
The final reason to paint a concrete pond is to give it a pleasing appearance. An unpainted concrete pond doesn’t look good as the color of concrete is not black. Most of the pond owner wants their pond to be black because is a pond with a black bottom looks the best.
Epoxy Paint or Rubber Sealant – Which One To Choose For Your Pond
If you have a smooth concrete pond and no problem with the budget, you should go for the epoxy paint. Epoxy paint makes it easier to clean the pond and prevents algae growth in the side as it is very smooth. It also takes very little time to cure. Again there is no need to apply any primer if you use it.
Liquid rubber is recommended when you have a rough finish in your pond, like an unfinished brick pond. It also saves you some bucks when it comes to coverage per gallon. But it takes a longer time to cure than the epoxy. Again algae growth is more than the epoxy as the surface isn’t smooth.
Whatever paint of sealer you choose for your pond, make sure it is safe for fish and pond plants. Also, make sure it is durable because you don’t want to paint your pond every year.