Plants are living organisms, and like any living organism, they are susceptible to disease. From fungal diseases to bacterial infections, there are many different diseases that plants can fall victim to. Even the most tightly run hydroponics garden can fall prey to root rot and powdery mildew. However, indoor gardens grown in a tent are less susceptible than gardens using soil. As long as the water is clean and air is circulated and controlled for humidity, the chances are much lower than soil-based gardens.
The common diseases found in indoor gardens can be narrowed down into five categories: fungus, bacteria, viruses, water molds, and nematodes.
The most important thing the gardener can do is to make sure that preventative measures are being taken. Make sure that plants have access to enough clean water and (circulating) air, with the right amount of humidity. You want your plants to be healthy enough to fight diseases on its own before you have to take additional measures to protect it. Prevention is key, but the next important step is keeping a close eye on your plants for any signs of wilting and drying, even though you are providing adequate amounts of water and nutrients. These may be signs that the plant is starting to fall prey to disease.