When organic growers think of hydroponics, they mostly assume that organic principles and organic growing are totally incompatible. Really, nothing could be further from the truth. Just because you choose not to use soil, that doesn't mean that you can't grow vegetables and other plants using strictly organic materials. In fact, some hydroponic growers report that it is actually easier to grow organically in a hydroponics system than through other methods. Hydroponic growers even have several different kinds of organic nutrients and fertilizers available.
Bat Guano – But guano has long been a popular fertilizer because it is rich in organic nutrients. There are two primary kinds of bat guano: those that come from insect eating bats and those that come from fruit eating bats. The guano that comes from insect eating bats is usually very rich in nitrogen, which means it is a fantastic organic fertilizer for promoting plant growth. The kind that comes from fruit eating bats is usually much richer in phosphorus, which means that they are more beneficial for budding and flowering. In addition to the nutrients, bat guano also contains beneficial microbes that can help improve the health of your plants.
Seaweed or Kelp - the ingredients in liquefied seaweed have certain compounds which have been shown to stimulate growth. This completely natural organic nutrient can help stimulate chlorophyll production in hydroponically grown plants. It can also stimulate the beneficial bacteria in your reservoir, which can help protect your plants from harmful bacteria and increase nutrient uptake.
Fish Meal – Fish based fertilizers have a lot of proven benefits for hydroponically grown plants. In some larger hydroponics systems, some people even keep live fish right in their reservoir to use them as a natural fertilizer source. In addition to the organic nutrients that they provide, fish fertilizer can provide enzymes and essential oils that can protect and strengthen your plants. If you want to give your plants an extra boost, you can also use it as a foliar fertilizer, meaning that you can apply it directly to your plants' leaves.
Earthworm Castings - In a traditional soil organic garden, gardeners often work to encourage earthworms to live and eat beneath the soil of their garden. This is because the excrement, or castings, or the earthworms creates a powerful fertilizer that provides plants with a lot of nutrients that they can use to create bigger yields. Hydroponics growers don't use soil, but they can still take advantage of the many benefits of fertilizing with earthworm castings. Many hydroponics retailers sell liquefied earthworm castings that you place right into your reservoir.
While you many find that some products do contain just one kind of these organic nutrients, most contain a blend of them. These blends can very potent, as they give your plants several different kinds of organic nutrients that can help them grow significantly. Some are even specially formulated to improve a specific aspect of your plant's development, such as those that can improve the size of your buds or your yield.