Both hydroponic fertilizers and those intended for use in soil contain the three major nutrients, nitrogen, phosphorus and potassium. The major difference in hydroponic fertilizers is that they contain the proper amounts of all the essential micro-nutrients which fertilizers intended for use with soil do not. The plants are expected to find these elements in the soil, assuming that the trace elements are in fact present. Problems can arise for the plants if any or all of the micro-nutrients are not present in the soil or are depleted by successive (or excessive) plantings. Hydroponic fertilizers are usually in a more refined form with fewer impurities making them both more stable and soluble for better absorption. Organic fertilizers, in most cases, are very different than either hydroponic or soil fertilizers both in composition and how they deliver the nutrient to the plants. Organic fertilizers rely on the synergistic action of bacteria and microbes to break down nutritional substances for easier uptake by the plants. Hydroponic and soil fertilizers provide nutrients in a ready-to-use form. While once, they were mutually exclusive, in recent years a number of outstanding organic fertilizers have hit the market in formulations refined enough for use in hydroponics.
How complicated is hydroponic gardening?
It can be but it doesn’t have to be. Hydroponics can be as incredibly simple as growing a single plant in a hand watered bucket or nursery pot, using any number of inert growing mediums. No automation, electricity or grow lights required. Of course, the potential to go high tech is limited only by your imagination and budget. Virtually every aspect of garden management can be automated and should you so desire, monitored and controlled with your laptop or cell phone from the other side of the world. Dare to dream. Most hobby oriented hydroponic systems are somewhere between the two extremes mentioned above. The average, home hydroponic system usually consists of a few basic parts: a growing tray, a reservoir, a submersible pump to water the plants, a simple timer and an air pump and air stone to oxygenate the nutrient solution. Of course, light (either natural or artificial) is also required.
What is “growing medium”?
Growing medium is the material in which the roots of the plant are growing. This covers a vast variety of substances which include Rockwool, perlite, vermiculite, coconut fiber, gravel, sand and many more. The growing medium is an inert substance that doesn’t supply any nutrition to the plants. All the nutrition comes from the nutrient solution (water and fertilizer combined). You can therefore, easily control everything the plants receive. The strength and pH of the nutrient solution is easy to adjust so that the plants receive just the right amount of food. The watering/feeding cycles can be controlled by an inexpensive timer so that the plants get watered on schedule, as needed.
Is pH important in hydroponics?
The control of pH is extremely important, not only in hydroponics but in soil as well. Plants lose the ability to absorb different nutrients when the pH varies. The ability to quickly and easily test and control pH in hydroponics is a major advantage over dirt gardening, where testing and adjusting the pH is much more complicated and time consuming.
In addition to treating the liquid waste excreted by fish, the solid waste must also be treated. This is done by concentrating and flushing the solids out of the system. Removing solids reduces bacteria growth, oxygen demand, and the proliferation of disease. The simplest method for removing solids is the creation of settling basin where the relative velocity of the water is slow and particles can settle at the bottom of the tank where they are either flushed out or vacuumed out manually using a siphon. However, this method is not viable for RAS operations where a small footprint is desired. Typical RAS solids removal involves a sand filter or particle filter where solids become lodged and can be periodically back-flushed out of the filter. Another common method is the use of a mechanical drum filter where water is run over a rotating drum screen that is periodically cleaned by pressurized spray nozzles, and the resulting slurry is treated or disposed. In order to remove extremely fine particles or colloidal solids, a protein fractionator may be used with or without the addition of ozone (O3.)