<h1>How to Test Water Hardness in your Aquarium and Fish Pond</h1>

How to Test for Water Hardness

Fish need specific tank conditions in order to survive. For aquarists, the need to ensure that all essential water parameters that influence water quality are continually met is of prime importance.

One of these important water parameters is water hardness. Testing your fish aquarium tank water regularly for water hardness can definitely promote the health and well-being of your fish.

There are water testing kits that you can easily order from an online aquarium store. These test kits have been designed to assess tap water and freshwater aquarium for general hardness (GH) and carbonate hardness (KH).

Methods Used to Soften Aquarium Water

Water softeners work by removing almost all the magnesium and calcium from the water.

Water-softening devices work via an ion-exchange process wherein ions that cause water hardness exchange places with sodium and chloride ions that are bound to zeolite or resin filter.

The MarinaInternal Filter i25 comes with a specially-designed Power Cartridge that provides a 3-stage filtration system—mechanical, chemical and biological. It contains a zeolite chamber where toxic ammonia is removed when water passes through the chamber.

Peat can also be used for water softening because of its ability to absorb and sequester calcium ions while releasing humic and tannic acids into the water and lowering the pH.

Other effective measures to lower water hardness include reducing the fish load, increasing filtration, increasing the amount and frequency of making water changes.

Methods to increase water hardness

• Addition of crushed coral and coral sand

          PISCES coral sand contains calcium carbonate that can raise the water hardness and also serve as a buffer for the pH.

• Baking Soda, Marine Salt, and Epsom Salts

Aside from raising the water hardness, adding these substances into a freshwater aquarium can also raise the pH value. Baking soda can add plenty of bicarbonate ions to the water. It should be combined with some Epsom salt and calcium chloride to increase water hardness.

• Calcitic Gravel

Calcitic gravel can boost water hardness however it is only effective up to pH 7.5. Many aquarists add calcitic gravel in hard, alkaline aquariums to serve as a form of insurance in case aquarium condition goes awry and the pH drops dramatically.

General guidelines of acceptable General Hardness (dH) and Carbonate Hardness (KH) for different types of freshwater aquariums, tropical marine aquariums, and ponds.

Freshwater Parameters	Freshwater Community	African Cichlid	Freshwater Plants & Discus	Brackish	Pond
Alkalinity (Carbonate Hardness)	4 - 8 KH	10 - 18 KH	3 - 8 KH	10 - 18 KH	4 - 8 KH
General Hardness	4 - 12 GH	12 - 20 GH	3 - 8 GH	12 - 20 GH	4 - 12 GH

Marine Parameters	Suggested Level: Reef Aquarium	Suggested Level: FOWLR Aquarium	Average Level: Coral Reefs
Alkalinity	8 - 12 dKH	8 - 12 dKH	6 - 8 dKH