Maintaining Healthy Hydro Roots to Avoid Root Rot
By Keith "Tree Frog" Bouchard 21 September 2021
Many growers start with soil and after some successes, move on to try other methods that promise adventure and the lure of even greater rewards. Hydroponics offers accelerated root growth which leads to vigorous, high performing plants. Bigger, faster, stronger is a typical description from some hydro enthusiasts who swear they’ll never go back to growing in soil. On the other hand, hydro is typically less forgiving than soil. One of the largest threats to growing with hydroponics is root rot, which stagnates growth and eventually kills plants or entire crops. A couple of simple precautions will prevent would-be disasters in the modern indoor garden.
Beat the Heat
In summer, watch out for root rot, which can occur when water temps rise above 64°F. When roots rot, not to be confused with tinting from some types of nutrients or additives, they begin to tint and then brown and die off. Pathogens and bad biology are the cause, and they thrive in the warmer water. Typically, water temps run about 10 degrees cooler than room temps, so gauge the health of your hydro system by simply measuring your ambient room temperature. Start with proper growroom heating and cooling. If average temps are above 75°F, additional cooling may be needed. Consider adding a water chiller to the reservoir if necessary.
To properly thrive using any grow method, environmental control is key. Pathogens can multiply in water and grow mediums when room temps constantly exceed 75°F. Keep garden temps between 60-85°F, targeting 70-75°F. This will keep water temps in the correct range for roots and plants to grow vigorously while keeping away the bad biology that causes root rot and negatively affects plants.
Control the Environment
Especially with hydroponics, gardeners see a noticeable difference in growth rate and overall results when environmental factors are well maintained. Ideally, your growroom shouldn’t be affected by what season it is outside. In addition to maintaining a comfortable environment, be sure to keep a generally clean room, free of any constant moisture, hot spots, or other undesired microclimates.
High summer temperatures can cause problems for any growroom, especially hydro setups where sitting water tends to heat up throughout the day. The water tanks become thermal masses that will help with heating in winter and work against you in the summer. For added cooling, place reservoirs in darker, cooler areas outside of the direct light.
If room temps cannot be maintained in the correct range, consider a reservoir chiller or additional air conditioning. Set up the hot exhaust of the A/C unit to blow outside of the growroom. Raise lights further away from the top of the canopy on days that excessive heat cannot be tamed. If root rot still occurs, purchase hydroponic-specific cleaning and preventative products from your favourite grow store to fight it by adding them to your reservoir. Consider regularly using a minimal amount as a preventative measure.
Winters are generally more forgiving for indoor gardeners, just be sure to maintain room temps to avoid slowed growth. Keeping daytime temps above 60°F and nighttime temps above 50°F degrees should maintain proper growth rates and avoid problems.
Providing these basic essentials of hydroponics will empower indoor growers to achieve maximum yields for minimal effort. Don’t be intimidated, as simple hydro methods can be set up with ease. Keep the water and nutrients well aerated and maintain a pH between 5.6 and 6.4. Again, try to keep ambient room temps in a range between 65-80°F. If growing in the correct climate, try hydroponics outdoors as well. Whether indoor or outdoor, be sure to top off warm tanks with cold water to prevent potential problems. Just get growing and enjoy the benefits that hydroponic growing offers. Have fun and happy gardening!