How To Fix Hard Water In A Fish Tank

Knowing how to fix hard water in a fish tank is crucial if you plan to keep fish that prefer soft water. Doing this sounds complicated – but is actually much simpler once you’ve understood what makes aquarium water hard.

The “hardness” and “softness” of aquarium water refers to the amount of dissolved minerals in it, such as calcium, magnesium, carbonates, etc. The more minerals water contains, the “harder” it is. If the water contains only a slight dose of these minerals, it’s “soft”.

To illustrate, if well water comes from a place that has a lot of calcium deposits, it’s most likely hard water. On the other hand, rain water doesn’t contain any minerals in most cases, which makes it soft. While tap water can be either a little soft or a little hard, this varies from place to place.

Depending on the fish you own, it’s very important to understand which type of water they need. Certain fish can only thrive in hard water, and vice versa for soft water. For example, pH balance is elevated in hard water, which might not be suitable for your fish, so it’s very important to do your research regarding your fish’s needs.

How To Fix Hard Water In A Fish Tank

In order to make hard water soft in a fish tank, what you have to do is take the minerals out of it by using a softening agent.

If you need to make your tank’s water go from hard to soft, here are a few DIY methods on how to do it:

Method 1: Using rain water 

This is a common method in which uncontaminated rain water is used to fill a tank instead of tap water. The rain water needs to come from a place with unpolluted air. You also need to make sure that it hasn’t passed through places which might contain traces of minerals or chemicals.

Method 2: Adding driftwood

Using driftwood is another common way to soften hard water. Before using it, you have to boil it to ensure that it’s 100% clean and free of tannins and toxins. Once you’ve finished purifying the driftwood, we recommend soaking it in clean water for a few days before putting it in your fish tank.

Method 3: Using an R.O. unit

This method is the most convenient, as it’s quick and efficient. Reverse Osmosis (R.O.) units eliminate minerals, metals and contaminants from water. They purify water by getting rid of contaminants and other elements through chemical processes, converting it from hard to soft.

Method 4: Using peat

Using peat is also a popular method for softening hard water. First, boil the peat to ensure that it doesn’t contain any impurities. Next, soak the peat in a bucket full of the water that you want to soften and wait a few days. Wherever you choose to soak the peat, make sure that the water isn’t stagnant. The more it moves, the quicker and more efficiently the peat will strip it of the minerals and metals. Using an air stone increases the movement of water, so it’s not a bad idea to add it to the water if you want to speed up the process.