Hydroponic nutrients are generally considered safe when used according to the manufacturer's instructions. Most hydroponic nutrient solutions contain a blend of mineral salts that provide essential nutrients to the plants. However, it's important to use high-quality nutrients that are specifically designed for hydroponic methods, as some conventional fertilizers may contain harmful additives or heavy metals. It's also important to monitor the pH and nutrient levels of the solution regularly to avoid nutrient imbalances or toxicities.