Will A Black Storage Tank Make Your Water Hotter?

When choosing the best water tank for your rain harvesting system, you need to consider a variety of factors such as size, volume, base requirements, and the color of your tank. When it comes to color, one of the most popular is black as it keeps sunlight out. In this post, you’ll find out how black tanks affect water temperature, whether or not this matters, and what alternative options you have.

Why Black Water Tanks are the Most Popular

Depending on the material, a black tank will often block more sunlight from entering the tank than lighter-colored tanks. Since algae need sunlight to grow, tanks that do not let sunlight in prevent algae from growing in your tank. This keeps your water cleaner and useable. For this reason, black tanks are generally preferred by customers who are setting up a rainwater harvesting system.

How Black Tanks Affect Water Temperature

It is well known that dark colors absorb heat, and black water tanks are no exception. No matter the material, in direct sunlight, a black tank will heat up the water. When a dark tank absorbs heat, the heat is naturally distributed throughout the water in the tank. The more sunlight the tank is exposed to, the hotter the water will get. If you are looking for room-temperature or cool water out of your tank, this can be a problem.

Pro Tip: The location of the tank will have an impact on the water temperature.
If you have the option, you can place your tank under a deck or other structure to keep it from absorbing any sunlight at all.

Does Hotter Water Matter?

Since the temperature of the water coming out of your black tank will be affected by direct sunlight, you should consider your intended use. If you plan to treat your water and use it for potable purposes, likely the temperature will be irrelevant. For most non-potable purposes, the water temperature shouldn’t be much of an issue.

Can Light Colored Tanks Keep Sunlight Out?

If you want your water to be cooler straight out of the tank, a lighter color may be your best bet (except that a light tank will let sunlight through the sidewalls and allow algae to grow). Generally, this is the case, except for tanks that have LIGHT-BLOCK™ Technology. This technology allows lighter color tanks like beige and mist green to keep sunlight out. I would recommend you use one of these tanks as it gives you the choice of different colors while keeping your water clean and safe. These tanks also have a UV PROTECT™ Exterior which stops solar radiation from degrading the interior of the tank.

We hope this post has helped you understand how black tanks affect the temperature of your water and guide you in choosing the right tank color for your rainwater harvesting system. As mentioned in the post, location also has an impact on this, so be sure to consider this when placing your tank. If you have any further questions, feel free to leave a comment.