Organic hydroponics is a hydroponics culture system based on organic agriculture concepts that does not use synthetic inputs such as fertilizers or pesticides. In organic hydroponics, nutrient solutions are derived from plant and animal material or naturally mined substances. Most studies on the topic have focused on the use of organic fertilizer. Benefits There is increased consumer interest in organic hydroponics, as the global organic market is expected to grow nearly 25% from 2017 to 2024. Due to decreased use of nitrate based fertilizers, nitrate levels in organic soil-based crops found to be lower than in conventional crops. Furthermore, beneficial microbes have been found to induce resistance against soil and air-borne diseases, and can outcompete harmful organisms to promote resilient systems. Organics also present some health benefits. Since soil-based organic agriculture uses less pesticides, it has lower toxic residues than plants grown with inorganic fertilizer by approximately 75%. While there is inconclusive research on whether it is more nutritious than conventional agriculture, a meta analysis of plant nutrition found that soil-grown organic food is higher in antioxidants. Challenges Organic hydroponic systems often have lower crop yields relative to conventional hydroponics. A 2001 study found that lettuce grown in organic solution yielded much less and grew at a significantly slower rate than lettuce grown in conventional solution. Furthermore, organic hydroponic systems are prone to large pH fluctuations, with limited input products that can be used to balance them out. In addition, organic hydroponics requires very high amounts of knowledge, experience, and investment compared with conventional agriculture. Successful use of organic fertilizers can be more difficult in hydroponic systems than in fields, where beneficial microbes in the soil help to break down organic fertilizer into nutrients that are usable by the plant. When grown in soilless substrates, organic fertilizers may not be readily broken down by microbes and can inhibit plant growth. However, with recent innovations, scientists have created organic hydroponic systems that produce growth and quality comparable to conventional hydroponics. It is important to note that there are many types of organic fertilizers, crops, and hydroponic systems that can perform differently. Therefore, it is important to avoid overgeneralizing claims about the efficacy of organic fertilizers in hydroponics. Fertilizers When evaluating the effectiveness of organic fertilizer, it is important to keep in mind the huge difference in effectiveness between different types of fertilizers. Besides differences between types of fertilizers, the mineral content