Sharing of planting and breeding experience-Water

Since the nutrient concentration required for orchids is only 1 to 6 of that of most fast-growing plants, it is necessary to understand the composition of the water used for watering orchids. Although pollution-free fresh Rain Water is the best, it may be hard to get.

The investigation of water sources can be divided into two parts:

1. Total salt content

2. analysis of the content of various salts.

Salt content:

The more accurate and practical method to determine the salt content in water is to measure the electrical conductivity (EC) of water. Pure water is almost non-conductive, but most of the salts contained in water are conductive, and the conductivity or conductivity of water is directly related to the concentration of salt in water. The unit for measuring electrical conductivity can be expressed as MHOM (reciprocal of resistance unit ohms) or Siemens (S). For orchid water, the conductivity you measure is very small, a few parts per million of Siemens, called micro-S, symbolized as μ S 50 or 50 μ S, 100 or 100 μ S. The instrument used to measure electrical conductivity is called a conductivity meter. The instruments commonly used to measure the electrical conductivity of liquids are divided into two types, one is MHOM (μ S), and the other is total dissolved salt (TDS). TDS is accurate in coefficient and reflects 1/1000000 content (PPM). But TDS confuses the fact that different salts have different electrical conductivity (for example, urea hardly conducts electricity when soluble in water). Siemens, a unit of electrical conductivity, is mostly used in horticulture, but TDS is mostly used in urban water source analysis reports to express the analysis results. The two readings can be easily converted, roughly 1000 μ S equivalent to 666TDS. The choice of conductivity meter can depend on the kind of plant you cultivate. For orchids, a reading of 1-1999 μ S with temperature compensation is ideal, because the conductivity is affected by temperature.

Because orchids require low nutrient concentration, it is very important to use water with low salt content. The following table shows the water quality assessment for orchids:

Evaluation of electrical conductivity of water

= =

Less than 50 μ S is good.

50-100 μ s. Good.

100-200 μ S is OK.

More than 200 μ S difference

Analysis of the content of various salts:

The amount of salt in the water is as important to us as the total salt content. In developed countries, some associations of orchids or other plants will provide their members with the results of various salt content analysis of local water sources. The data unit is PPM, that is, the number of milligrams of a certain salt per liter of water. Water in many areas is relatively hard, both high in salt and mostly high in calcium and magnesium carbonates. For example, there is little rain in most parts of the north of our country. Too much calcium and magnesium will be toxic to orchids. It is not difficult to understand that the use of low-salt water can better control the balanced nutrition of orchids.

By the way, remind our northern orchid friends: in order to neutralize the alkalinity of hard water, it is dangerous to add organic acids (oxalic acid, citric acid, etc.) to the water! Yes, these organic acids do reduce the electrical conductivity of water at the same time, but the conductivity does not reflect the content of all salts, such as urea mentioned earlier. It seems inappropriate to add other salts to water which is already too salty. I also hope that everyone will act cautiously.

As I have little talent and learning, there is something improper in the article, please criticize and correct it.

Beijing du Xiao