
Hydroponics is a relatively new technique of crop cultivation that does not require the use of soil. However, many growers tend to overlook one crucial aspect: the quality of water. It’s literally the most important element in any hydroponic system.
Chlorine and chloramine are your biggest foes here. To keep a nutrient-rich water supply for your crops, the water needs to be clean and free of harmful chemicals. Different types of hydroponic water filtration systems include RO systems, carbon filters, and spin filters.
However, the right hydroponics water filter depends on the condition and volume of the water and your budget.
In this post, we’ll explore the several ways you can purify water you use to grow your plants. By understanding how each filtration system works, you can make an informed decision about which method suits your needs best.
Why Filter?
Instead of soil, hydroponic plants rely on water to get their nutrients known as TDS or total dissolved solids. This means that they also require a consistent supply of clean, pure water for them to grow.
You can also water your plants with distilled water, but they also need minerals and other nutrients for survival and growth. These minerals include potassium, carbon, phosphorus, nitrogen, magnesium, and sulfur, and others.
The minerals also come in various concentrations. So, depending on what your plants need, you have control over the nutrients you supplement them.
Besides supplying your plant with the right amount of nutrients, the water should also have the right pH level of 5.5 or above. However, for most plants, 6 would be the highest.
Also, tap water is always a staple for many growers. While it’s safe to use, it can contain high PPM (parts per million). It’s the number of minerals present in that water. If there’s high PPM in the water, it can mess up the balance of nutrients. As a result, it becomes toxic to your plants and causes them to die.
Filtering your hydroponics’ tap water can solve this issue. It removes fluoride, chlorine, chloramine, and other chemicals. These are treatments that make your home’s water supply safe for cooking and consumption, however, they are not good for your plants.
Think about growing your plants in the soil. The soil filters those chemicals. But in hydroponics, there’s no soil. Your plants are completely dependent on the water. The water needs to have the needed microbes so your plants can grow and bring in higher yields. The presence of chlorine and chloramine on the water kills them.
Again, hydroponic water filtration systems can solve these issues. Thankfully, there are different ways to do it.
Different Types of Hydroponics Water Filters
Hydroponics water filters keep your plant’s water supply clean while allowing them to get the nutrients they need for growth. But before you decide on which filtration method is most suitable for you, consider the amount of water your plants need.
You must also prepare to dedicate whatever amount of time and effort is required to making sure that your hydroponics systems are running smoothly.
Now, here are a few types of hydroponics water filters you can try:
Reverse Osmosis Water Filter

The reverse osmosis or RO filter is highly effective in eliminating pollutants from water. This water filtration method uses a semipermeable membrane, which has pores that allow large molecules and ions through.
Through this process, a reverse osmosis filter removes chemicals, heavy metals, and other contaminants. It can also remove bacteria, viruses, and other microbiological organisms that your plants probably won’t even need. An RO filter is the most common type of method used in hydroponics, however, it has its cons.
For one, it is expensive to run. Reverse osmosis filters consume a lot of power. Another thing is that the water that goes through an RO filter needs to be pre-filtered, so there’s the extra step. The reason why is that you don’t want your filter’s membrane to get clogged.
But if you have a large hydroponic system, reverse osmosis filters will do a great job at purifying huge volumes of water. These filters also give you the flexibility to tweak whatever amount of nutrients your system requires.
And while RO filters are expensive to run, they provide a range of benefits that makes them a popular option to many growers. Plus, they have a longer lifespan than most types of water filtration systems.
Pros:
- Removes all chemicals, heavy metals, microorganisms, and other contaminants from water
- Great for large hydroponics; can filter large volumes of water quickly
- Longer lifespan than most water filters
- Allows you to add the right amount and type of nutrient solution back into the system
Cons:
- Expensive to run since it uses a lot of power
- Water needs to be pre-filtered before it passes through the RO filter
Carbon Filters
This is a more affordable type of water filter for hydroponics. In many households, it’s a staple. It’s a really cheap way to get odorless, sediment and chlorine-free drinking water. A carbon filter for hydroponics does the same thing—but for your plants.
Carbon filters use activated carbon to filter out rust, silt, sediment, volatile organic compounds (VOCs), and odor, all while keeping all the beneficial microbes and bacteria in your growing zone.
Chlorine, especially, is one of your biggest foes when it comes to growing plants with hydroponics. Carbon filters eliminate such a chemical. Plus, they are low maintenance.
With this type of water filter, you can choose between an activated carbon filter and catalytic carbon filter. But, what’s the difference?
Activated carbon filter. Do you ever wonder why your carbon-filtered drinking water is safe to drink? Well, this type of filter contains minerals that are beneficial to health, such as ion, calcium, and magnesium. However, it can’t tackle smaller molecules, which makes RO a better option for most growers.
All that being said, activated carbon filters are more affordable than reverse osmosis systems and even catalytic carbon filters.
Catalytic carbon filter. Water that is free of chlorine and silt is critical for cultivating healthy plants. This type of carbon filter is more effective in removing trihalomethanes, VOCs, and hydrogen sulfide than activated carbon. However, it’s more expensive than activated carbon filters but still more financially doable than RO.
Pros:
- Generally affordable
- Removes chlorine, sediment, rust, and other contaminants while keeping the water healthy for your crops
Cons:
- Only useful for larger molecules
Hydroponics Spin Filter

If your water supply comes from a decomposing well, this may be a great option. Hydroponics spin filters filter out large and heavier sediments, debris, and dirt. Unlike a fine, micron sediment filter, this type of water filter uses a centripetal force that directs the water into a chamber.
How it works is it “spins” the water with that force and literally pushes the debris to the side of the chamber. The dirt and sediments then settle down at the bottom or onto a container, as the filtered water flows through the system.
You can then empty the chamber by opening the valve and allowing the collected debris to exit. This is a necessary step to guarantee that it works properly when you need it.
Hydroponics spin filters are typically used as an essential pre-treatment step for setting up your hydroponics system. However, it can be a learning curve if you’re not familiar with the method.
Pros:
- Great for removing heavier and large debris and sediments that most ultra-fine water filters can’t.
- Good for water pre-treatment
Cons:
- A learning curve
Water Purification Systems
This could be anything that uses various technologies and ways to filter water for hydroponics. The method may involve a combination of filters including sediment filters, UV filters, and other forms of water treatment such as ozonation or chemical disinfection.
Since the biggest threat to your crops is chlorine, dechlorination may be the first thing to look into. Aside from that, sediments can also affect your crop’s growth. You don’t want them to accumulate in your system. So, if this is your main concern, sediment filters will take care of it.
UV filters are quite straightforward. This type of water filter for hydroponics uses UV light to deliver chemical-free water to your plants. UV filters also work best when paired with other filtration techniques to eliminate particulates and other impurities.
FAQs
Can You Use Tap Water for Hydroponics?
You can definitely use tap water for hydroponics provided it’s properly treated, however, you need to consider the quality. For chlorinated tap water, make sure to let it sit in the sun for 24 hours. You may also use filtration systems to eliminate chlorine and chloramine.
Another process you can try to ensure that your tap water is effective for hydroponics is running it through a purifier or mixing it with RO or distilled water. This will lessen the concentration of substances in the tap water.
Learn how to keep your water reservoir cool in your hydroponic system in our guide here.
What Is the Best Filter for Hydroponics?
RO is the best hydroponic system. Growers use the reverse osmosis method to remove contaminants and minerals. For eliminating odors and organic compounds, go with carbon filters. But if the water you use has a significant amount of sediments or debris, consider sediment filters.
Deciding in which water filtration your hydroponic systems needs eventually depends on the water quality.
Final Thoughts
There are various types of hydroponics water filters to explore. Whether you opt for an RO system or a simple carbon filter, they all share the same role of maintaining water quality that’s safe for your crops. Investing in the right hydroponics water filter system can help your plants grow and flourish.
If you have any questions about the different techniques we’ve discussed in this post, let us know and we’ll be happy to help you. Good luck!