Sanitize and Sterilize: How to Clean Your Hydroponic System

The most critical step to a successful hydroponic harvest is one most growers hate: sanitation and sterilization. Cleaning your hydroponics system is not the most glamorous part of cannabis cultivation, but it is crucial to ensure the mistakes and pathogens from one grow don't contaminate the next.

For those that need a reminder about the value of a clean hydroponic system, here it is. We also cover a basic step-by-step process for sterilizing your hydroponic equipment and sanitizing the grow space.

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Sanitation is the basic cleanliness of your grow space, including the hydroponic lines and tank. It's about cleaning up dead leaves and other waste organic matter. It's about mopping up spills and wiping down grimy surfaces. 

Sterilization is about killing all microbial life, including fungi, bacteria, and other pathogens. This process reduces the risk of disease from one harvest to the next. There are two methods of sterilization: chemical wash and heat. 

Due to the sheer volume and types of equipment that need sterilization, most growers stick with disinfecting chemicals like bleach and hydrogen peroxide,

Bacteria, fungal spores, and other microbial pathogens thrive in a damp environment like the one you're currently growing cannabis in. If left to its own devices, your grow room would very quickly turn into a swamp creature rife with mold and mildew.

Keeping a clean grow room ensures your success from one crop to the next. Any pathogens thriving in your first round won't make it through to the next. 

In a clean environment, plants don't have to waste energy fighting off pests and disease. Instead, they can focus their resources on healthy growth and prolific flowering. 

A clean (and sterilized) grow room affects not only the living plants but also the harvest. If you've ever found a cured bud that was actually rife with mold, likely those spores existed in the grow room. 

Ongoing cleaning procedures help eliminate the places where these organisms like to live. Sterilization of the hydroponic set up between grows and sometimes, during a grow, can eliminate much if not all of the risk.

Before introducing plants into your grow room, use your chosen cleaning agent to wipe down all surfaces. This can include tables, walls, and fixtures. Sweep up any dirt or debris lingering from the last grow, and use a wet mop to sanitize the floor.

Scissors, pruning tools, grow nets, and other items can spread disease. Even if your entire room is clean and sterilized, a simple cut from a pair of dirty scissors can introduce fungal or bacterial infection. 

Use diluted solutions of bleach or hydrogen peroxide to wipe down each tool. You can also dunk some items into a container filled with one of these solutions. 

Remember to use safety glasses and gloves while working with these solutions. Follow the label instructions for dilution!

Keep in mind, reusing substrate increases the risks of bringing pathogens into your next crop. If you decide to reuse your growing medium, take the time to understand the proper protocols for the specific substrate.

Remove all organic material, like roots and dead leaves, from the substrate. Fill a large tub with either a bleach or hydrogen peroxide solution. Soak the substrate for at least one hour. Flush the substrate with fresh water at least two or more times to clear the lingering solution. 

Hydroponic water lines and drains may become clogged with constant use. Vacuum out your drains to remove any built-up residue. Then, blow out your lines to remove any problematic particles which could lead to backups and blockages.

While not always necessary, you may want to run your system with that same diluted hydrogen peroxide solution to sterilize the inside of the lines and filters. Again, flush with fresh water at least two or more times.

One of the most important steps is to sanitize and sterilize the nutrient reservoir. It's a hot spot for microbial life, thanks to the constant supply of water and nutrients. 

First, drain the reservoir, and use a scrubbing brush or pressure washer to remove all residue. Once sanitized, use your hydrogen peroxide or bleach solution to sterilize. Flush with fresh water to clean out the residue from these solutions.

Depending on the size of your hydroponic system, you could be working with one or more filters throughout the operation. Some filters require sterilization regularly, while others may be fine with a quick clean. Because there are so many possible options, it's best to refer to an owner's manual for specific instructions.

The little-known fact about a hydroponic system is the ongoing need for cleanliness. Even if you've now run several grows through the same system with minimal sanitation, one rogue spore could deliver a death blow to the next round.

Nobody wants to lose your plants to bud rot or powdery mildew. Take the time to maintain a clean hydroponic space, and incorporate a complete sterilization protocol between set-ups.