How to Control Pests: Setting Up Your Hydroponic Garden

July 17, 2018


Growing Hydroponics is a worthwhile and thoroughly rewarding experience. The crop yields are generally much higher than conventional methods and require much less space. One of the problems with gardening in general, however, is dealing with pests and disease.  

Your hydroponic garden is just as susceptible to invading pests and diseases just like a convention garden is, but the change in equipment brings a change in critters and other bacteria, which can dramatically affect your crop if you’re not careful.


Since hydroponic gardens are normally islands of their own and cut off from the world, they’re actually far less prone to contracting an insect, fungal, or bacterial pest or disease.  

The problem, however, is that if one of these organisms finds its way into the garden, it lacks the competition found in nature to keep it in balance. A small pest invasion will quickly take over and destroy a crop if left unchecked in a hydroponic garden set up.  


The usual suspects-

The same insect pests that affect outdoor gardens will affect indoor ones. Thrips, spider mites, nematodes, aphids, fungus gnats, and mealybugs are all common outdoor AND indoor garden pests.  


Thrips are small, greenish black insects that move at lightning speed and tend to jump off your plants leaves whenever you try to look for them and as a result, they are rarely seen. Identifying thrips relies more on finding the damage they cause than seeing the insect itself.  

Thrips will use special mouthparts to scrape away the surface of the leaves in order to get to the sugary, juicy insides. The leaves will look scaly, and silver. Large infestations will start to cause growth defects in the leaves, and older leaves will begin to die off.  

Thrips are best dealt with by blocking off the roots of your plants with plastic. Part of their life cycle involves dropping off into the root zone to grow as larvae before crawling back up the plant to feed on the leaves. Blocking off this crucial stage in their life cycle is one of the simplest and most effective ways of eliminating thrips from the hydroponic garden. 

Spider Mites

Spider mites are in the arachnid family, and can actually spin webs just like a spider. These tiny insects are hard to see with the naked eye but will form large colonies quickly which are shrouded in web structures which they use as highways to get from leaf to leaf. These webs protect them from sprays and help to create a small microclimate for their eggs. 

Spider mites need to be attacked vigorously and early. Use insecticides containing neem, malathion or pyrethrum for best results and repeat every 3 days until they are completely gone and monitor closely for signs of their return or remission.  

Mealy Bugs

Mealybugs are white, fluffy looking insects that attach themselves permanently to the leaves or stalks of your plants, where they spend the rest of their short lives sucking the sugary juices from your plant.  

Mealybugs are very difficult to treat because their hard shells protect them from being exposed to insecticides. They reproduce quickly and will feed on a wide range of plant species.  

The best way to manage mealybugs is to use pyrethrum insecticides to target the younger generations that lack the hard protective shells and to attack adults individually with a cotton swab soaked in alcohol. This is tedious, but one of the most effective ways to deal with mealybug infestations.  


Aphids are pioneers. When colonies grow large enough, they begin producing offspring with wings, which they use to fly to other areas in search of new food sources. Once they find a new spot (which may be the inside of your hydroponic garden) they only need a single insect to start a colony. Aphids don’t need a male and a female to produce young and are often found to be born already pregnant. This makes it very easy for them to grow incredibly large colonies from a single insect.  

Aphids have soft swollen bodies, making them easy to kill by either pinching them with your fingers or through insecticide use. Their rapid reproduction and large numbers are what makes them difficult to eliminate completely.  

Common Diseases In Plants

Hydroponic Mildew

Powdery mildew is a fungal disease affecting the leaves. It’s very common in indoor gardens, especially areas with poor airflow, and cooler temperatures. You can identify powdery mildew from the dusty, fuzzy appearance it leaves on infected areas. Powdery mildew will not grow on anything but leaves, so if you find something that fits this description in the soil, it is something else.  

Treating powdery mildew is generally quite easy. Antifungal agents can be sprayed onto the affected areas and generally result in the complete elimination of the fungus after just a single treatment. Sometimes a follow-up treatment or 2 will be needed. Once eliminated, it can help to increase the airflow of your hydroponic garden by adding circulation fans or adjusting current ones.



Pythium is one of the worst diseases that you will inevitably face in your hydroponic setup. It is a fungus-like organism that infects the roots of your plants. It’s both highly infectious and lethal.  

The best treatment for this disease is prevention. Ensuring that there are no\ dead or rotting roots in your system, using enzymes or hydrogen peroxide.  

Changing the water regularly, and making sure it remains in constant motion with air stones, and water pumps will go a long way in preventing pythium infection in your garden as well.  


Knowing what can infect your plants, and how to identify them make it much easier to find a solution to the problem. All of the pests and disease discussed in this article are very common, and at least one of them is likely to be faced by any hydroponic gardener no matter how many precautions you take. This is why regular inspections of your plants are crucial if you want to catch these infections early and deal with them long before they become a problem. 


For more information get in contact with one of our representatives at Hydroponic Generations today!