How to soften hard water in an aquarium

Categories: Blog, General

For fishkeeping enthusiasts, maintaining a delicate balance of proper water pH in your home aquarium is an intensive process. From setting up your aquarium to preparing the water and introducing your fish, each step is another careful task in maintaining a happy home for your fish friends.

 

Yet even in the most stable environments, fish tanks can be susceptible to the effects of buildup that comes from very hard water. Let’s consider what hard water is and how we can practically protect our fish to avoid any major issues.

 

What is “hard water”?

Hard water is defined as water that has dissolved compounds like magnesium and calcium. This is because most water sources, especially in the UK, are lakes, aquifers underground, and rivers. The water passes through rocks like limestone, which leaves it rich in minerals.

 

A water’s GH, or general hardness is measured by figuring out the ppm (parts per million) of these mineral compounds in water. In a freshwater aquarium, this should be a moderate reading of 3-6 GH or 50-100 PPM for aquatic plants and fish to thrive.

 

If you host tropical fish in your aquarium, they prefer slightly higher hard water concentrations that range from 6-12 GH or 100-200 PPM. Different fish species around the world can adapt easier than others and may be able to tolerate these compounds to a certain degree.

 

These compounds in our tap water, however, are easily visible to humans when the water is heated in order to be used for public consumption. It creates a high mineral content that leaves the commonly known residue on the surface of our dishes, skin, and hair.

Extreme hard water residue may be unpleasant on our own bodies, but it’s way more harmful to our fish.

Why is hard water harmful in an aquarium?

The first major problem overly hard water causes is the disturbance to the delicate balance of water’s pH in an aquarium. This pH level is crucial to sustaining your fish’s health, and the high mineral content of hard water makes their environment change, leaving them susceptible to diseases and can even prove fatal.

 

Another stress this causes to fish is the way that hard water creates the ideal environment for algae to bloom. Overactive algae production puts a strain on the filtration system and can make your fish seriously ill over time, starving even your aquatic plants of necessary oxygen within the water.

How do I help soften hard water in my fish tank?

Now that we know how bad hard water is for our marine friends, how do we prevent it from ruining our fish tanks? Consider the following practical ways:

 

  • Add driftwood - Driftwood helps to lower the pH of water by releasing tannins into the water, naturally balancing the environment. It’s also an eye-catching addition to any decor you have in your aquarium and proves a cosy hiding place for fish.

 

  • Consider your substrate - Using substrates like aquarium soil and gravel can help soften or sustain your water so hardness levels don't rise. Coral should be avoided for hard water, as it can add more minerals, making the problem worse.

 

  • Reverse Osmosis (RO) Filtration - By far, the most effective and elaborate water filtration systems for softening hard water are reverse osmosis systems. These water filtration systems pass water through membranes and filter out nitrate, chlorine, phosphate, and more, giving you the purest water for your fish tanks. You then have a blank canvas to remineralise the water in the way you want.

 

Maintain Your System at Its Best

It’s important to note that no matter the tactic you use to help soften hard water, filtration systems provide an integral foundation for your fish’s wellbeing. Keep an eye on the water hardness of you tank and make sure to replace parts of your filtration system regularly to keep it working as it should.

 

At Finerfilters, we are experts in proper filtration for your fish-keeping needs. Browse our full range of aquarium systems and replacement filters for aquariums.