Basic parameters for healthy plants

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What is EC?

[ Bluelab Pulse Meter measures EC in soil ]

EC (electrical conductivity) is a measure of the total amount of nutrients available to plants.

When nutrients dissolve in water, they break down into ions, which carry an electrical charge. This allows the solution to conduct electricity. Pure water is not a conductor because it does not contain ions. The more ions there are in a solution, the higher its electrical conductivity.

How is EC measured?

• It is measured in mS/cm (milliseeds per centimeter) .
• Unlike pH, there is no universal scale – at least four different ones are used:
  • EC (Electrical Conductivity): 1 mS/cm = 1 EC
  • PPM 700: EC × 700
  • TDS / DS / MS (PPM 500): EC × 500
  • CF (Conductivity Factor): EC × 10

👉 It is important to know which scale your appliance and fertilizer supplier uses.

⚠️ EC shows the total amount of nutrients , but not their specific composition.

🔎 For a detailed introduction, see the article: "What is electrical conductivity and how is it measured?"

Recommended product: Bluelab Pulse Multimedia EC/MC Meter

 

 

The role of EC in nutrient absorption 🌱

[Healthy green leafy crops in a large greenhouse]

At the most basic level, nutrients must be available for plants to take them up. Measuring EC gives you an idea of the total amount of ions – or nutrients – in your system at the moment.

It may be tempting to feed your plants as much as possible so they always have access to food, but this can have disastrous consequences. Every crop has a preferred EC range in which it grows optimally.

👉 Different crops require different nutrient solution strengths depending on the growth phase. It is a good practice to do research on the specific crop or consult a specialist to ensure you maintain the correct range throughout growth.

EC not only affects nutrient uptake, but also the ability of plants to take up water. If the conductivity is too high, plants may not be able to take up enough water.

• In hydroponics : measure the EC of the nutrient solution when mixing, as well as after it has been absorbed by the plants.
• In soil : It is more difficult to measure the strength of fertilizers as they take time to break down. However, it is possible to measure EC directly in the root zone with a soil EC meter.

👉 EC values fluctuate - so it is important to measure daily , especially on warm days when plants may only absorb water.

Hydroponic growers should make a habit of completely emptying the tank and replacing the nutrient solution every 7–10 days . This prevents nutrient imbalances that can lead to deficiencies or toxicities.

Effects of improper EC ⚠️

As can be seen from the tables, each crop has its own preferred EC range. If plants are exposed to inappropriate values, they will begin to show symptoms of poor health.

If EC is too low:

• Leaf discoloration (yellow or brown tones)
• Holes or brown necrotic spots
• Slow growth of roots and foliage
• Reduced harvest
• Deformed or twisted leaves

If EC is too high:

• Toxicities – interveinal chlorosis, thickened or necrotic roots, brown spots, change in leaf size.
• Sodium/salt burn – burnt tips and edges, twisting or curling of leaves.
• Lack of water – wilting of leaves and stems, loss of shine, slowed growth.

👉 Instead of treating symptoms, measure EC regularly – regardless of the growing method.

Recommended tools for measuring EC:

• Bluelab Conductivity Pen
• Bluelab Pulse Multimedia EC/MC Meter
• Bluelab Truncheon Nutrient Meter
• Bluelab Combo Meter

How to lower EC?

[ Water ]

• In hydroponics : add pH-balanced water to dilute the salts. Very high values may require a complete flush of the system and replacement with a weaker solution.
• In soil : Water liberally with pH-balanced water until saturated and drained. Measure the EC of the soil runoff and repeat if necessary.

How to increase EC?

[ EC measurement with Bluelab Combo Meter ]

• In hydroponics and soil : simply add more nutrient solution or fertilizer.
• Always measure EC after adding fertilizers and mixing the solution to ensure you do not exceed the target range.

⚠️ This is different from treating a specific deficiency – for such cases, see the nutritional deficiencies guide.

Recommended product: Bluelab Combo Meter

Why is temperature important for plant growth? 🌡️

[The thermometer measures the temperature in the garden]

pH and EC are critical parameters for plant health, but temperature also plays a crucial role for optimal growth. It is also the parameter that is most often overlooked.

Temperature can refer to both the air around the plants and the temperature of the nutrient solution or irrigation water, which directly affects the root zone .

The roots are where two vital processes take place:

• water absorption;
• absorption of nutrients.

👉 To be effective, roots must be maintained in an optimal temperature range .

The role of root zone temperature in nutrient uptake

[Young seedlings under LED lighting]

Root zone temperature determines the rate at which plants absorb nutrients. If left out of control, it can lead to serious yield losses.

• Optimal range: 18–22 °C (65–72 °F).
• If the water is too warm → less dissolved oxygen → risk of oxygen starvation.
• If the water is too cold → shock to the roots, slowed metabolic processes, growth retardation.

As with pH and EC, each crop has its own preferred temperature range for its roots.

Effects of improper root zone temperature

• In soil : temperature fluctuations are smaller because it acts as a buffer.
• In hydroponics : roots are more vulnerable to sudden changes.

❌ If the temperature is too high or too low for an extended period, plants can fall into a "dormant" state - growth and yield drop dramatically.

At too high a temperature:

• Accelerated metabolic reactions → risk of toxicity (discoloration of leaves, thickened/necrotic roots).
• Increased risk of pathogens and diseases.
• Reduced dissolved oxygen content → problems with plant respiration.

At too low a temperature:

• Slow metabolism → nutrient deficiencies.
• Symptoms: interveinal chlorosis, stunted growth, brown edges or spots, leaf necrosis.
• Similar to high temperatures – risk of diseases and infections.

How to lower the temperature of the root zone 🌬️

[Growers inspect plants in a shaded environment]

In hydroponics:

• Use chillers with a built-in thermostat.
• A popular option is stainless steel cooling coils placed in the tank.
• Insulate the tank to maintain more stable temperatures.

In soil:

• Plant cover crops for shade and to reduce evaporation.
• Use awnings or nets in the summer.
• Apply mulch or synthetic ground covers as insulation.

How to increase the temperature of the root zone 🔥

[Healthy seedlings grown on mulch]

In hydroponics:

• Use an additional tank in which the water can be heated before entering the system.
• In cold climates – heating tanks or mechanical heaters (with a heat exchanger, as the solution is corrosive).
• Insulate the tank and raise it off concrete surfaces.

In soil:

• Installing heating cables or using thermoregulated heating mats .
• Mulching in winter - prevents cold and retains heat.
• Additional coatings (plastic, organic or synthetic insulators).

👉 Maintaining the correct pH, EC, and temperature values is the foundation of successful plant cultivation. They determine whether plants will be able to absorb the nutrients and water needed for healthy and productive growth.

👉 Make it a habit to measure these parameters regularly and adjust them as needed - this will save you a lot of trouble and guarantee better results.