You have a number of choices when it comes to choosing a concrete sealer. Of course, just because there are a lot of options does not mean they are suitable for the job of sealing your pond. You need to have the best concrete pond sealer for your specific needs.
What Should You Consider?
As you are searching for the sealer, think about your application. How will you be using it? Since you are getting it to seal a pond, the best concrete sealers for you will be those that are fully waterproof and that are long lasting. Some sealers will need to be reapplied each year, and this is especially true with those that will be underwater for most of the year. You want a sealer that is going to last a long time and that is truly waterproof.
Another hugely important factor that you have to consider is whether the sealer is toxic or not. If you are going to be using this in a pond, which will likely have plants and fish in it, then nontoxic is the only option you can choose. Otherwise, it will injure and even kill the plants and fish that you put into it. Always check the sealer to see if there are any volatile organic compounds, typically solvents, that are listed on the packaging. These are bad for the environment, and they can kill the fish in the water.
Even though it might look cured and stable, if the sealer has solvents, there is a good chance that it is leeching into the water. It might take some time, but it will eventually cause issues with the health of your fish. Another issue with sealers that contain solvents is that when they cure, they can shrink, and that means they could cause cracks.
You will also want to get an idea of the tensile bond strength of the product when you are trying to choose the best concrete sealer. Those that are able to bond firmly with the concrete have less of a chance of peeling away later. If you have a sealer that peels, it will mean you have to repair it in a few years. Ideally, you will have a tensile bond strength that is even greater than the strength of the concrete, so you can be sure it will last as long as you have the pond.
When choosing the best concrete sealers, you will also want to think about the elongation break strength. This refers to how much the material can bend and move before it cracks. A high elongation break strength will mean there is less of a chance of a crack occurring after you apply the sealer.
Never simply choose the first sealer that you find. If you really want to have the best concrete sealer, it pays to do the legwork and to learn about the product before you use it on your pond. This will ensure that you have a solid seal that will keep your pond, as well as the fish and plants, safe.