Water hardness is a number that represents the mineral content in your water. The higher the number, the harder your water is. This guide will explain everything you need to know about hardness and how it affects planted aquariums.
Hard water and high pH makes it difficult for many aquatic plants to absorb important nutrients, such as iron and manganese. However, amazon swords, water wisteria, hygrophila, cryptocoryne and other species can grow well in hard water because they demand fewer insoluble nutrients.
Naturally lower your aquarium hardness by soaking dechlorinated tap water in peat moss, Indian almond leaves or driftwood. A more precise method would be to dilute tap water with reverse osmosis (RO) or distilled water or to use remineralized RO water.
You can increase your aquarium water hardness by adding crushed coral, using hard tap water, or by using remineralization products such as Seachem Equilibrium. It’s best to make these changes before adding fish to avoid fish loss.
The most consistent way to test aquarium water is by using a liquid test kit. These tests provide accurate results, measured in either degrees of hardness or parts-per-million. You can also use test strips or bring a water sample to your local fish store.
Tap water is safe to use in a planted aquarium and with fish, as long as the water has been dechlorinated and has the right water parameters. It’s important to choose aquatic plants and fish species that are suitable for your tap water’s pH and KH levels.
The term “alkalinity” refers to the sum of all bases that buffer against aquarium pH swings, with carbonate being the most frequent and important base. Carbonate hardness, or KH, only measures the concentration of carbonate and bicarbonate bases.
KH measures an aquarium’s carbonate hardness, or the degree to which it is able to buffer against pH fluctuations. GH stands for general hardness, which measures the number of dissolved calcium and magnesium ions. GH is crucial for the growth of certain fish species.