I want to try hydroponic lettuce at home, but I don’t know how to set up simple hydroponic equipment and precautions. The molded ones on Taobao are either not too ugly or not too expensive. Then follow the tutorial below, friends~ Get melon seeds, peanuts, soda and snacks ready~ Take care of your children~ Let’s get started~
The general steps of hydroponics are:
1. Select utensils; 2. Prepare culture medium; 3. Grow seedlings and transplant; 4. Culture.
The following is a step-by-step description:
1. Choose utensils
I found a lot of hydroponic containers in a search on a certain website, with prices ranging from tens to hundreds, for example
The actual principle is as follows:
Or the picture below will make it clearer:
A = submersible pump
B = Overflow tube (when the water level in the PVC pipe rises above the top of the pipe, it can flow back to the water tank
C = water storage tank (any plastic tank that can store more than 10 liters of liquid)
D = water inlet pipe
E = highest water level
F = Planting basket (used to place plants)
G = root (aerial root)
H = water + hydroponic solution (fertilizer)
J = water pipe
L = Overflow liquid flows back from the PVC pipe to the water storage tank for recycling)
X = 80mm diameter PVC water pipe
Y = Power socket with timer switch (controls water pump to supply power every day)
It seems 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 and is of suitable size (actually I recommend a larger one, which will be discussed later). For example, foam fruit boxes, drink bottles, plastic lunch boxes, finished yogurt and jelly shells. In addition, be careful not to use things that easily conduct heat as hydroponic containers, such as tin troughs and cans, because these containers will cause the temperature of the nutrient solution to change and lead to denaturation.
For example, like this: put the fruit in a foam box and plastic cup, punch a hole in the foam box, the diameter should be enough to fit the plastic cup
Or this: disposable lunch box and foam board (pore size is 1~2 cm radius)
Or this: plastic flower pots and yogurt boxes
In addition, the key to hydroponics is to supply oxygen to the roots of plants soaked in water, because water does not have small gaps like soil for air to penetrate, so it can only be done by increasing the dissolved oxygen in the water. There are many ways to increase the oxygen content in the water, which can allow green algae to grow in the water (therefore, it is best for the hydroponic container to be transparent to facilitate the photosynthesis of green algae.
Suddenly I realized that everyone mightI don’t know how green algae grows in the water: there are trace amounts of algae spores attached to the air, and green algae are photoautotrophic organisms that grow when exposed to sunlight (carbon dioxide and water) to produce oxygen or allow water to flow. Get up, then we need a water pump to circulate water, and a timing power switch to control the number of cycles of the water pump (if you have goldfish at home, you can use goldfish oxygen pumpinstead).
I think if your culture device is not very large, oxygen produced by green algae will be enough. I checked that the power of water pumps used by others is very small, "generally between 12W and 25W. In addition, the hydroponic system uses a timing adjustment device, and the power-on time is about half an hour to an hour every day." In addition, I think you can also use a short and large container, which can increase the contact area between water and air, which is beneficial to dissolved oxygen.
2. Prepare culture medium
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 nutrients in hydroponics come from water. This is different from soil cultivation. The soil contains various plant elements. Even if a certain element is lacking, it will gradually show up. If hydroponics is lacking a certain element , showed up quickly. Plants with too much nitrogen will grow wildly, while plants with too much phosphorus will turn purple and cause premature aging. Most of the roots of plants with excess manganese turn brown and brown spots appear on the leaves. Most of the leaves with excess boron become yellow or scorched. Some vegetables like magnesium, so add more magnesium, and some vegetables (such as cruciferous rape) like sulfur, so add more sulfur.
The culture solution formula for lettuce 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 (sulfurZinc acid)0.22mg/kg,
CuSO4 (copper sulfate) 0.08mg/kg,
(NH4)6Mo7O24?4H2O (ammonium molybdate) 0.5mg/kg
After preparing the nutrient solution, pay attention to sealing and storing it. 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 wrap it with newspaper outside to block light and place it in a cool place. Especially for solutions containing trace elements, attention should be paid 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 in the gardening market or Taobao, and just dilute it in proportion. The advantage is It is simple to use. The disadvantage is that the capacity of each bottle is small, and it is finished after a few uses. The cost is high. The key point is that I don’t know what its formula is (in fact, the most important thing is this. Apart from having fun, isn’t it just for safety? ~). Just follow Taobaos instructions and mix the nutrient solution yourself. It costs about two or three yuan a month~
In addition, you should pay attention to the choice of water for hydroponics. It is best to choose tap water, because river water, rainwater, etc. contain many minerals and heavy metal pollutants, and the pH value cannot be detected. It may also contain many spores of miscellaneous bacteria or algae.
During the hydroponics process, plant roots will secrete substances that dissolve into water, which can easily breed bacteria. Some bacteria in the air also fall into the water and multiply. In order to ensure the healthy growth of plants for a long time, the nutrient solution must be replaced regularly (about 10 days). about).
3. Seedling cultivation and transplantation
First, let’s talk about how to choose a variety. When growing vegetables under natural conditions, it is best to ask about this when buying seeds. Off-season vegetable cultivation requires comprehensive regulation of temperature, humidity, and light. Leafy vegetable varieties are the best, such as Chinese cabbage (rapeseed), water spinach, tomatoes and cucumbers can also be grown, but the requirements are relatively high. I strongly recommend watercress here!! It’s very easy to grow!! You can have 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 raise seedlings. One is to place the seeds on paper towels soaked in water or something with strong water retention such as a biochemical sponge. The seeds will germinate quickly, but the seedlings of this method will not grow for a few days.
Or it would be better to put it inside a sponge with two slits, like this:
Another method is to use sand rivers or loose soil to raise seedlings (actually this method is also used to raise seedlings in large-scale agricultural production). In order to facilitate subsequent transplantation, sand and loose mud are less likely to damage the roots.
When the seedlings grow to 5~10cm, it is time to transplant the seedlings~
At this time, prepare some sponge to fix the stem of the seedling, and make a slit in the middle of the sponge, like this:
When the vegetables grow larger, you can remove the small sponge with the cutout.
4. Cultivation
@王伟quen’s water level control and “Why should we use foam boards? Can we use plastic boards?”
Good question~
The foam board is used to fix the seedlings, and plastic boards should also work. However, foam board is easier to cut, and when your container is large and you can’t find anything to hold it, you can let it float on the water, as shown on the far right of the picture below:
However, I am a little worried that the chemicals on the foam will diffuse into the culture solution and be absorbed by the plants. There is no solution yet.
In addition, when it comes to water level control, if you are growing vegetables and the like, the height of the general culture solution is about 10cm. It is best to let the root neck come out of the water a little bit so that the roots are exposed to a little air. 10 Change the nutrient solution every day or so, and put it in the containerRemove any green algae that grows. During these 10 days, if the evaporation of the culture solution decreases, just add water to the container. Do not add nutrient solution, otherwise the concentration of the nutrient solution in the container will increase and the plants will burn.
It is more troublesome to maintain the root system of vines such as tomatoes and cucumbers. They need to be shaded (it should not necessarily be shaded, probably to prevent green algae from growing up to compete for nutrients?), heat preservation, oxygenation, and root pruning, such as Like this:
There is another problem, that is, vegetables are usually in summer in the later stages of production. The temperature begins to rise, and it is easier for vegetables to infest insects. At this time, you need to use some pesticides. However, I am studying biology, and I am not very knowledgeable about this aspect. I don’t know which medicine should be used for which disease. I will check it out later and tell you, or someone who is a farmer student can tell you~
Let’s talk about co-culture of hydroponics and fish. This is relatively difficult to achieve for hydroponic vegetables.
First we have to solve dissolved oxygen. The growth of fish requires a large amount of oxygen, and the oxygen consumed by the roots of hydroponic plants is also obtained from the water. This creates a conflict between the two oxygen intakes, which often causes fish to die due to lack of oxygen. So one or two fish in a hydroponic container is enough, and they are 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 raise fish in a small space, and I think it is pitiful that the fish will be stuck by roots wherever they swim.
Secondly, the nutrient formula and concentration in the water will also affect the growth of fish. The concentration of the nutrient solution is low and does little harm to the fish (but as we mentioned above, it is impossible to raise fish in the hydroponics mode if the nutrient concentration is too high). For some fish that are difficult to raise, you do not need to put the nutrient solution in the plant. ofJust add fertilizer in the planting basket, that is, add appropriate drops of nutrient solution to the matrix of the planting basket every once in a while.
In fact, from a biological perspective, it is not conducive to the growth of fish or plants. Before choosing to grow hydroponic vegetables with fish, you should consider whether you want to raise vegetables or fish, so I do not recommend it.
Finally, here are the results of netizens’ hydroponic vegetables:
Author: Shuen KUNG
