Yes, good Hydroponics Nutrients can help plants to fight against the disease. Just like humans have its disease-fighting system inside the body, the same like plants have. If your plant is healthy and has the power to fight against the disease then without any other method the plant itself heals and fights against that disease.   Maintaining the proper PH levels and Nutrients in the system can help the plant to fight and using the right growing medium is also important in hydroponics.