The Importance of EC

There are some grow room tools that you can't or shouldn't be with out and the Bluelab Nutrient Truncheon - is a must have for all hydroponics enthusiasts! Lets see why......

Monitoring EC is essential

EC stands for Electrical Conductivity and is measured in mS/cm or millisiemens per centimeter. Taking this measurement estimates the total amount of solids dissolved in water - before we add any nutrients. When growing in Active Hydroponics systems due to evaporation and plant nutrient uptake - the EC rises - how fast this will happen depends on plant size, the volume of solution and the enviroment. If the EC is too high the feeding solution becomes toxic - which if left will kill your plants. In the case of Passive and Run to Waste Hydroponic Systems it is still vital to measure the run off - EC and PH - and increase or decrease accordingly, this is the only way to monitor the EC in these systems accurately.

Accurate nutrient feeding

EC monitoring allows you to control the nutrient strength in your feeding solution - this will create optimal conditions in the root zone of your plant allowing the maximum uptake of nutrients into the cellular structure. If your EC becomes high it is harder for your plants to take up water to meet their basic needs. tail tail signs of this are that the leaves start to curl up and turn brown at the edges - aka - nutrient burn.

You will never under or overfeed your plants again, EC readings removes away the guess work and provides you abilitilty to meet individual plant feeding needs.

Grow Environment and EC

Your growroom environment has a big effect on your EC - for example under cool and low lighting conditions - the EC can be raised to reduced stretching. Under high periods of heat and low humidity - the EC can be lowered to ease plant stress successfully.

This is a art but once perfected you will be able to regulate your EC to improve aromas, colours and flavour of your finished fruit or vegetables!

So what EC range should I aim for and when?

The first thing you need to know is the current EC of your tap water. This is imperative - if you intend to mix the correct EC strength levels of your solution. Although tap water does have an EC - it contains sodium and chlorine - neither minerals are beneficial to plant growth. Therefore once you have the tap water EC - you can then add appropriate amount of nutrients to achieve the desired EC.

So depending on your flowers or vegetables this is going to be varied...that said the below ranges are from a hydroponic grower with more than 20 years experience.....

Hydroponic growing EC range for seed to flower:

  • EC: 0.8-1.3 for seedlings
  • EC: 0.5-1.3 for clones
  • EC: 1.3-1.7 under vegetative phase
  • EC: 1.2-2 during flowering

The Run Off - Passive / Run to Waste / Hand Watering

30% Run off – Drain away, Remove By Hand or Wet Vac


Tap Water

Never just use straight tap water - (if you use tap water- then ensure you leave it for 24 hours for the chorline to evaporate).....

IF TAP WATER EC IS 0.6 OR HIGHER – the use a *Reverse Osmosis Unit (Or use Calmag to tap water to make E.C 0.45 but no higher than 0.5).

Remember different varieties of might require significantly different values of EC.

Always start growing at a low EC and then build this up as quickly as possible to make sure you provide for the plants nutrient requirements properly, building a stronger plant.

Always empty your nutrient tank on a regular basis - this is because plants take up mineral ions at different rates in various stages of growth - so the nutrient solution naturally becomes unbalanced overtime. Your EC reading is informing you of the quantity of dissolved solutes in the solution - not - how much of any element remains in the the solution.

In your plants final weeks of cultivation it requires hardly any nutrition - any nutrition provided is to keep the EC stable.

*For information on Why you should feed your plants RO Water (Reverse Osmosis) - read my previous post here.

Bluelab Nutrient Truncheon makes testing EC simply...

So you can quickly see why the Bluelab Truncheon is a must have for all hydroponic growers - once you start to monitor the EC levels - your going to grow only healthy strong plants with improved flavour and natural aromas.

Using the Bluelab Nutrient Truncheon is easy - just place the probe head into the solution for 30 seconds to allow it to reach the same temperature as your water then remove from the solution and place back in to take the reading as indicated by the flashing lights on the side of the unit!

Bluelab Nutrient Truncheon