A concrete water tank can be a good choice for storing rainwater that you'll use to water your lawn, garden, or livestock, and for use in an emergency, such as a brushfire or house fire. There are many advantages to having such a tank on your property, but it's still good to know what's involved in its repair and maintenance over the years before you decide that it's the right choice for you. Note a few factors to consider about a concrete water tank so you can discuss this option with an installer.
One major advantage of this type of water tank is that concrete itself can be poured in any shape; you can have an installer design an oblong tank or one with a bend, so it can be worked around an outbuilding or landscaping feature. The material is also fireproof, so it won't melt, smoke, emit toxic fumes, or combust if there is a fire on your property. Concrete also has a slow rate of heat transfer, so water in a concrete tank is kept cool; in turn, it won't evaporate as easily and won't be a good host to algae and other contaminants.
One of the most important steps to maintain a concrete water tank is sealing it; this involves putting a coating over the inside of the tank so that the material doesn't absorb the water it's holding and won't soften, crumble, or crack. There are a few different types of sealants you can use for concrete; some are sprayed on like a paint, and others may be applied with a roller. If the concrete tank is very large, the spray application may be a better choice, but you might need a professional concreter to apply it so that the layers of sealant are even and no part of the surface is overlooked.
Even with the best sealant, a concrete tank may eventually crack. Very small cracks can be repaired with a concrete filler, but for larger cracks and holes, the surface may need to be drilled so that an epoxy can be injected into the concrete itself. This will help seal the damaged areas inside the material, and keep the tank from splitting completely. The drilled areas are then filled in and patched over. It might also be best to leave this job to a professional so you don't split the concrete while drilling it, and so that the epoxy is applied properly.