According to krishijagran.com: One of the advantages of indoor hydroponic gardening is that pests are significantly less likely to attack your plants. However, “much less susceptible” does not imply “impenetrable,” because bugs are widespread in hydroponic farming.
Spider mites are not favorable to hydroponic cultivation. Since these small pests are only a millimeter in diameter, their webs are more visible than the mites themselves. If you notice a spider mite infestation, act swiftly because it will rapidly proliferate and might eventually take over your whole garden.
Spider mites make their living by sucking plant sap and fluids. This destroys the structure of the plant and makes it susceptible to disease. If you find yellow, withering leaves on your plants, look for webbing cause you may have a spider mite infestation.
If your infestation is too extensive for trimming but still manageable, a soap spray may be a solution. Spray three teaspoons of insecticidal dish detergent (such as Castile, Ivory, or Murphy’s Oil) with a gallon of water on afflicted areas. Repeat every day for one to ten days. Consider applying pyrethrum, a mite killer manufactured from chrysanthemum flowers, for larger infestations.