Can You Use Tap Water For Hydroponic Plants?

Water is a key element of Hydroponic Gardening. Therefore, it’s not surprising that a frequently asked question from new hydroponic gardeners is:

Can You Use Tap Water For Hydroponic Plants?

It’s an excellent question, given that other options for water, such as distilled, reverse osmosis, and filtered water is costly and can require extra equipment and setup.

However, using tap water comes with its own set of challenges and requirements. In this article, we’ll walk you through the 3 main problems you may encounter when using tap water for hydroponic gardening. We’ll also show you how to solve them!

1. Problem 1: Chlorination
   Many towns and cities ensure tap water safety by adding chlorine or hypochlorite, which kills bacteria. As it turns out, it can be toxic to plants as well, stunting growth especially in sensitive fruits and vegetables such as strawberries and salad greens.
   
   Solution: The good news: Chlorine is highly volatile, evaporating quickly on contact with UV rays. You can accomplish this by exposing chlorinated water to sunlight for about 24 hours (depending on chlorine concentration). You can safely use the water for your plants when active chlorine levels fall below 1PPM.
   
   
2. Problem 2: Chloramine
   
   A combination of chlorine and ammonia, Chloramine is especially important to remove if you’re utilizing an aquaponics system, as it is toxic to fish. Much like chlorine, it is used to destroy bacteria but is more challenging to get rid of.
   
   Solution: Making sure your water is free of chloramine requires running it through an active carbon filter, such as a Brita filter or an RO unit specially designed to filter chloramines. Other solutions available on the market include campden tablets, or a chemical called sodium thiosulfate, commonly used by aquariums.
   
   
3. Problem 3: High PPM & Hard Water
   
   Once you’ve taken care of chlorine and chloramine, you now need to consider anything else that may be in your water, such as dissolved calcium, magnesium, and/or other elements. This is measured in parts per million (PPM). An excessive amount of these is called hard water and may put your plants at risk by causing an overabundance of minerals they may need only need small amounts of. It can also create problems by building upon your equipment, making it difficult to clean, or even causing malfunction.
   
   Solution: You can test your water using a PPM meter. In general, 200-300 PPM range shouldn’t cause too many problems for your plants. Anything higher than that, and you may need to run it through a filter or add distilled or reverse osmosis water to dilute it.

In conclusion, properly tested and treated tap water is a viable option for your hydroponic plants. A couple of treatments, like sunlight exposure for chlorination, or a filter for chloramine may be necessary, depending on your local tap water supply. It is also wise to test the PPM of your water, and filter or dilute if necessary. After that, your hydroponic plants should be happy and free to thrive in their tap water-filled beds!