Home Brands Products Deals Promo Finder Store Features Forums Add Review What's Knoji? Sign Up Login

Controlling Hard Water Levels in a Saltwater Tank

Knoji reviews products and up-and-coming brands we think you'll love. In certain cases, we may receive a commission from brands mentioned in our guides. Learn more.
Maintaining the appropriate hard water level in your tank is essential, because it can contribute a big deal in the survival of your pet fish.


There are many underlying factors needed to watch out for if you are going to engage in a hobby of having an aquarium. Aside from the types of fishes that you are going to put inside your fish tank, it is likewise very important to know the kind of water you are going to use.

One of the concerns that revolve around the water issue is the alkalinity, also known as water hardness. If you have a saltwater aquarium, maintaining the hard water level is very important.

However, due to some factors and the normal life course inside the fish tanks, hard water level can be affected. Acidic pressure from wastes inside the aquarium and other normal functions may decrease the pH level of the water and it could badly affect the fishes inside the tank. Controlling the pH level of water appropriate for a saltwater tank is therefore very important to keep the aquarium residents alive.

Maintaining Hard Water Levels

To be on the safe side, saltwater aquarium levels should be above pH 7, or somewhere at pH 8 to pH 8.4. This is the level tolerable for saltwater animals. Maintaining your tank at this level may be quite hard, especially for rookies to the aquarium hobby. But then, there are ways of maintaining the level of hard water in a saltwater aquarium. Below are some simple tips on how to do it:

Maintain good water movement in your tank. Make sure the water flow causes surface agitation as it drives out carbon dioxide out of the water and brings in fresh oxygen in the tank. Poor oxygen levels in your tank may indicate a low pH level.

Avoid overcrowding your aquarium. Having too many fish in your tank may affect the level of oxygen inside the aquarium. It also means that too much waste can lower the water's pH level. The ratio of one fish to 10 gallons of water is the ideal.

Use the right substrate. Aragonite sand or gravel can be a big help in maintaining a higher pH level in your tank. Once the pH level drops, aragonite will be dissolved and it will release minerals and elements that could stabilize the water alkalinity. It is always advisable to use substrates intended for saltwater tanks.

If all else fails in raising the pH level in your marine tank, there could be another option. You can try using some additives that can be easily purchased -- see next section for recommended products.

Other Products

Here are some of the products that you can use to raise pH levels for this purpose:

Kalkwasser - It is also known as calcium hydroxide. It is used to supplement calcium in the water and maintain a higher pH level in reef aquariums.

Mineral Blocks - There are commercially available mineral blocks that are effective in raising the water pH level. Some of them are the regular wonder shell (which contains elements and minerals needed in reef tank), Seachem marine buffer (which can raise the pH level of up to 8.3), Seachem Alkaline buffer (which can also raise pH level ranging from 7.2 to 8.5)

Baking Soda - Some aquarists also make use of baking soda, or sodium bicarbonate, to keep the level of hard water in saltwater aquariums. It can buffer at pH 8.0 to 8.2. But it should be used in correct amounts since it can also have negative side effects on your tank.

Maintaining the appropriate hard water level in your tank is essential, because it can contribute a big deal in the survival of your pet fish.


About This Article

Marky Chavez

Explore Top Fitness Equipment Brands

Expand more
Top-ranked fitness equipment brands