The steps of hydroponic culture are: 1. Selection of equipment; 2. Preparation of culture solution; 3. Seedling and transplantation; 4. Cultivation
A = submersible pump
B = Overflow tube (When the water level in the PVC pipe rises above the top of the pipe, can flow back to the water tank
C = water storage tank (any plastic tank that can store more than 10 liters of liquid)
D = inlet pipe
E = highest water level
F = Planting basket (for placing plants)
G = root (air root)
H = water + hydroponic solution (fertilizer)
J = water pipe
L = The overflowing liquid flows back from the PVC pipe to the storage tank and is recycled for reuse)
X = PVC water pipe with a diameter of 80mm
Y = power socket with timer switch (to control the water pump to supply power every day) looks troublesome? But in fact, the container can be selected according to the size of the planting area and the environment, as long as it does not leak water and the size is suitable (in fact, I recommend a larger one, which will be discussed later). Such as foam fruit boxes, beverage bottles, plastic lunch boxes, finished yogurt and jelly shells. In addition, be careful not to use things that are easy to transfer heat to make hydroponic containers, such as iron tanks and cans, because these containers will cause the temperature of the nutrient solution to change and cause denaturation. For example, like this: the foam box and plastic cup for fruit, punch holes in the foam box, the diameter should be just enough to fit the plastic cup;
In addition, the key to hydroponics is to supply oxygen to the roots of plants soaked in water, because water does not have the tiny crevices of soil for air to penetrate in, and it can only increase the dissolved oxygen in the water. There are many ways to increase the oxygen content in the water, which can make the water grow green algae (so the hydroponic container should be transparent to facilitate the photosynthesis of the green algae. There are traces of algae spores attached to the air, and the green algae is a photoautotrophic type. Living organisms, carbon dioxide and water will grow up with sunlight) to produce oxygen, or to make water flow. At this time, we need a water pump to circulate the water. We also need a timing power switch to control the number of cycles of the water pump (if you raise goldfish at home, you can Use goldfish oxygen pump instead). I haven’t tried even a water pump. Actually, I think if your culture device is not very large, the oxygen produced by Chlorella is enough. I checked the power of the pumps used by others is very small, “usually between 12W-25W, plus the hydroponic system adopts a timing adjustment device, the daily power-on time is about half an hour to an hour.” In addition, I think you can also use a short and large container, so that the contact area between water and air can be larger and beneficial to dissolved oxygen.
The essential elements for plant growth are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S) ), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), boron (B), chlorine (Cl). The main nutrient elements in hydroponics come from water. This is different from soil planting. The soil contains various plant elements. Even if a certain element is lacking, it will slowly manifest itself. If hydroponics lack a certain element, it will quickly Just show it. Nitrogen-rich plants grow wildly with leaves, and phosphorus-rich stems and leaves turn purple and age prematurely. Most of the roots with excess manganese are browned, and the leaves appear brown spots, and most of the leaves with excess boron have yellowing or scorching.
Some vegetables like magnesium should add more magnesium, and some vegetables (such as cruciferous rape) like sulfur should add more sulfur. The formula of lettuce culture solution is: Ca(NO3)2·4H2O (calcium nitrate) 589.3mg/kg, KNO3 (potassium nitrate) 886.9mg/kg, NH4NO3 (ammonium nitrate) 57.1mg/kg, MgSO4 (magnesium sulfate) 182.5mg /kg, K2SO4 (potassium sulfate) 53.3mg/kg, H3PO4 (phosphoric acid) 0.223ml/kg. Also add trace element formula: EDTAFe (EDTA iron) 16mg/kg, H3PO3 (boric acid) 3mg/kg, MnSO4 (manganese sulfate) 2mg/kg, ZnSO4 (zinc sulfate) 0.22mg/kg, CuSO4 (copper sulfate) 0.08 mg/kg, (NH4)6Mo7O24•4H2O (ammonium molybdate) 0.5mg/kg nutrient solution should be sealed and stored after preparation. It is best to have a brown reagent bottle with a rubber stopper or a frosted glass stopper. If it is a transparent container, it is best to cover the outer bread with newspapers and keep it in a cool place. Especially for solutions containing trace elements, pay attention to shading. The laboratory is easy to handle, but it is still difficult for ordinary people to get such things. You can choose the hydroponic nutrient solution sold on the gardening market or Taobao, and dilute it in proportion. The advantage is that it is easy to use, but the disadvantage is that the capacity of each bottle is small. , It is finished after a few times of use, the cost is high, the point is that I don’t know what its formula is (in fact, the most important thing is this, besides having fun with hydroponic vegetables, isn’t it just for safety~).
In addition, attention should be paid to the choice of water for hydroponics. It is best to select incoming water, because river water, rainwater, etc. contain a lot of minerals and heavy metal pollutants, and it is impossible to detect the pH value. It may also contain many spores of bacteria or algae. In the process of hydroponics, the plant roots will secrete substances that dissolve into the water, which is easy to breed bacteria. Some bacteria in the air also fall into the water to multiply. In order to ensure the healthy growth of the plants for a long time, the nutrient solution must be replaced regularly (about 10 days).
Nursery and transplantation
First of all, let’s talk about how to choose a variety. When you grow vegetables under natural conditions, it’s best to ask this when buying seeds. The cultivation of off-season vegetables requires comprehensive adjustment of temperature, humidity, and light. The best varieties of leafy vegetables, such as cabbage (cole), water spinach, tomatoes and cucumbers can also be grown, but the requirements are relatively high. I highly recommend watercress here! ! Very good kind! ! You can get a bowl of noodles in two days! ! Then there is seedling cultivation. If you choose to buy ready-made vegetable seedlings, this step can be omitted. There are two ways to grow seedlings. One is to put the seeds on a paper towel soaked in water or a biochemical sponge or something with strong water retention. The seeds will germinate quickly, but this method will not grow for a few days.
The foam board is to fix the seedlings, and the plastic board should also be possible. But the foam board is easier to cut, and you can make it float on the water when your container is big and you can’t find anything that can jam the container.
However, I am a little worried that the chemicals on the foam will diffuse into the culture medium and be absorbed by the plants. In addition, when it comes to water level control, if the height of the general culture medium is about 10cm for growing vegetables, it is best to expose the root neck to the water surface a little bit so that the roots are exposed to a little air, change the nutrient solution every 10 days, and put the container by the way. All the green algae growing in it are removed. During the 10 days, if the evaporation of the culture solution decreases, just add water to the container. Do not add the nutrient solution, otherwise the concentration of the nutrient solution in the container will increase and the plants will burn seedlings.
If it is a vine plant such as tomato and cucumber, it is more troublesome to maintain the root system, and it needs shading (it is not necessary to shading, probably to prevent the growth of green algae from competing for nutrients?), heat preservation, oxygenation, and root repair
There is another problem. Vegetables are generally already in the summer in the later stage of production. The temperature starts to rise and it is easier to grow insects. At this time, you need to use some pesticides. But I am studying biology myself, and I am not very researched in this area. I don’t know what medicine to use for what disease. I will check back and tell everyone, or who is a good friend who is a farmer will tell you about it~ let’s talk about it. The problem of co-cultivation of hydroponics and fish is relatively difficult to achieve for hydroponic vegetables. First we have to solve the dissolved oxygen. The growth of fish requires a lot of oxygen, and the oxygen consumption in the roots of hydroponic plants is also obtained from water. This presents a contradiction between the two oxygen uptake, which often causes fish to die due to insufficient oxygen. So one or two in a hydroponic container is almost the same, and it is a small fish of about 3cm. In addition, the dense root system in the hydroponic container affects the activities of the fish. Generally speaking, it is difficult to feed the fish in a small space, and I think it is pitiful that the fish must be rooted wherever they swim. Secondly, the nutritional formula and concentration in the water will also affect the growth of fish. The nutrient solution concentration is low, and it is not harmful to the fish (but as we said above, it is impossible to raise the fish if the nutrient concentration is too high in the hydroponic mode). For some difficult fish, you can leave the nutrient solution on the plant. Fertilizer can be added to the planting basket, that is, every certain period of time, the nutrient solution can be properly poured into the matrix of the planting basket.
In fact, from a biological point of view, it is not good for the growth of fish or plants. Before choosing hydroponic vegetables and fish co-culture, you should consider whether you want to grow vegetables or fish, so I don’t recommend it.