Electrical Conductivity (EC) is used in hydroponics to measure the strength of a nutrient solution by detecting the amount of dissolved salts in the water. In simple terms, the more hydroponic nutrients added to your reservoir, the higher the EC reading will be.

EC is one of the most important measurements in hydroponic growing because it helps determine how much nutrition plants need during each stage of growth. Young plants generally require a lower EC range of around 0.2–1.0, while mature flowering plants may require higher nutrient levels between 2.0–3.0 EC.

For hydroponic growers, EC is considered one of the most accurate ways to monitor nutrient concentration, although other measurement systems such as PPM, TDS, and CF are also commonly used.

pH, or Potential Hydrogen, measures how acidic or alkaline a liquid is and plays a critical role in hydroponic growing. The pH scale ranges from 0 to 14, with 7 considered neutral, lower numbers being acidic, and higher numbers being alkaline.

In hydroponics, maintaining the correct pH is essential because it directly affects how well plants can absorb nutrients from the nutrient solution. As hydroponic nutrients are added to water, they can raise or lower the pH, so growers must regularly monitor and adjust their nutrient mix to keep it within the ideal range.

Most hydroponic plants prefer a slightly acidic pH range between 5.5 and 6.5. If the pH drifts outside this range, plants may struggle to absorb key nutrients, leading to deficiencies, toxicities, and poor growth.

Using digital pH meters along with pH Up and pH Down solutions makes it easy for growers to maintain stable nutrient conditions and support healthy, vigorous plant growth.

EC (Electrical conductivity) requirements change as the plant grows from seedling into a mature plant. When your plants are young they require less food, so it makes sense that as the plant grows we increase the amount of food to fulfil the plant’s needs.

• Seedlings: 0.6 – 1.2 
• Vegetative Growth: 1.2 – 1.8
• Flowering/Bloom: 1.8 – 2.4
• Flowering Maturation/Flush: 0.0 – 0.3 

Maintaining the correct pH in hydroponic systems and coco coir is essential for healthy plant growth, nutrient uptake, and maximum yields. Most hydroponic plants perform best within a pH range of 5.5 – 6.5, with stable pH levels being critical throughout the entire grow cycle.

If pH fluctuates too far outside the ideal range, plants can struggle to absorb specific nutrients, leading to deficiencies, slowed growth, and reduced yields. Using a quality digital pH pen removes the guesswork and helps maintain stable nutrient conditions for optimal hydroponic performance.

Recommended Hydroponic pH Levels

• Seedlings: 5.5 – 5.9 pH
  
• Vegetative Growth: 5.5 – 6.0 pH
  
• Flowering/Bloom: 5.9 – 6.3 pH
  
• Flowering Maturation: 6.0 pH

Correct lighting schedules are essential for healthy hydroponic plant growth, strong flowering performance, and maximum yields. Most photoperiod plants require 18 hours of light and 6 hours of darkness during the vegetative stage to encourage vigorous growth and plant development.

Once plants are ready to flower, growers typically switch to a 12/12 lighting schedule — 12 hours of light and 12 hours of uninterrupted darkness. Maintaining complete darkness during the flowering stage is extremely important, as light interruptions can stress plants, cause them to revert back to vegetative growth, or lead to mutations that negatively impact final yields and flower quality.

Autoflower or day-neutral plants generally perform well under 12–16 hours of light per day throughout their life cycle. It is also not recommended to run grow lights continuously for 24 hours, as plants benefit from regular dark periods during growth.

Some hydroponic growers also choose to leave lights off for the final 36–48 hours before harvest to help improve final crop results.

How Long Should Grow Lights Stay On?

Vegetative Growth

Most photoperiod plants require:

• 18 hours ON
  
• 6 hours OFF

This lighting cycle is commonly referred to as 18/6.

Flowering Stage

To trigger flowering, most growers switch to:

• 12 hours ON
• 12 hours OFF

Also known as 12/12.

Autoflower Plants

Autoflower or day-neutral plants typically perform well under:

• 12–16 hours of light daily

Correct lighting schedules are critical for healthy hydroponic plant growth and flowering performance.

For optimum growth, it is best to maintain your nutrient solution at a temperature of between 18°C – 24°C

There are several possible causes for plants suddenly wilting or dying in hydroponic systems, including:

• Lack of water and/or nutrients
  
• Temperatures that are too high/low
  
• Insufficient light
  
• Root diseases and pathogens

This is usually caused by overfeeding i.e. giving your plants too high an EC before they are ready for it. It can also be caused by a buildup of salts/food within your growing medium. If you suspect either of these scenarios it’s a good idea to fully flush your plant then go in with a reduced EC.

This can be caused by a number of factors:

• Low oxygen levels due to lack of aeration or too much water.
• Nutrient deficiency
• The pH is too high/low.
• The solution is too hot/cold.
• EC too high/low

All of these prevent the plant from absorbing nutrients in the correct quantities.

It should be noted that towards the end of the flowering cycle it is normal for the lower leaves on the plant to start turning yellow.

Plants stretch when their light source is insufficient, humidity is too high or they are crowded by other plants.

Lowering or turning up your light, increasing air flow or spacing plants further apart are some good options.

It should be noted that for 14-21 days after the lights are changed to a 12/12 cycle your plants may ‘stretch’. This is more referring a period of further vigorous vegetative growth and should be anticipated.

• Vegetative Growth: 60–65% RH
• Flowering Stage: 50–55% RH
• Drying: 50–55% RH
• Curing & Storage: 55–62% RH

Excessive humidity for long periods will create undesirable conditions that are perfect for grey mould to thrive. Grey mould, once started, will quickly spread and affect your entire crop.

Using a hygrometer device mounted on the wall inside your hydroponic grow room will let you know at a quick glance what your humidity levels are. Humidity levels of just above 50% during flower is perfect and should not go above this. It is important to keep nutrient reservoirs covered at all times so that they do not contribute to higher humidity levels.

Humidity levels can be easily controlled as with temperature by using inlet & extractor fans to rid the room of heat or humidity. Generally, it is good to keep your grow rooms clean and dry. This will help prevent any mould problems.

While the lights are on temperatures should be maintained between 22°C – 28°C

When the lights are off temperatures are permitted to drop by 5 degrees or so.

It is best to avoid large temperature fluctuations in the growing space at all times. If temperatures fall outside the optimum range for too long development can be significantly stifled or worse.

The main purpose of ventilation in a grow room is to expel hot and humid air and to replenish CO2.

Finding the perfect balance between optimum temperature, humidity and CO2 can be tricky and thus investing in the right gear from the start is important.

A good quality variable speed extractor fan will serve you well. As a general rule, you want an extractor fan that can complete a total exchange of vapour within the grow room every 1 – 3 minutes.

Using EC and pH meters in hydroponics is highly recommended and plays a major role in achieving healthy plant growth and maximum yields. Without digital meters, growers are essentially guessing nutrient strength and pH levels, which can quickly lead to nutrient deficiencies, toxicities, poor growth, and reduced plant performance.

A quality EC meter helps monitor nutrient concentration, while a pH meter ensures your plants can properly absorb the nutrients available in the solution. Together, these tools allow growers to maintain stable hydroponic conditions and achieve more consistent, professional-quality results.

Depending on the type of system you are running and the plants feeding requirements.

For ease of control use a minimum of 45 ltrs per/m2 of growing area, less than this requires frequent adjustments.

Some systems like DWC (Deep water culture) actually have the plants growing in a large volume of water and nutrients, this type of system can be plumbed to an external reservoir that will top up your main system as the solution depletes.

Aerating the nutrient solution is a good idea. It guards against stagnant water, improves plant health and prevents bacterial infections. Aerating a nutrient solution will last far longer than one that is sitting flat. Generally speaking, if you are running a recirculating hydroponic system or intend to store a nutrient solution for more than 24 hours you should be aerating your nutrient solution.

The time taken to strike roots on clones varies according to the time of the year and the health of the clones and whether the method is manual or assisted About 5-12 days is usual for most manual methods.

Assisted methods include cloning machines that drastically speed up oxygen intake which in turn can force roots to form with 3-7 days.

The best water will have low salts or contaminants. Rainwater is probably best though normal tap water is usually satisfactory and convenient as long as it is under 0.3 EC

Most Australian tap water is valued between 0.0 - 0.3

Reverse osmosis is fast becoming a preferred method as well, the only downside is pH fluctuations (using a pH stabiliser will correct this) and the water after it is cleaned will require re-conditioning with a calcium magnesium additive.

The choice of grow light in your hydroponic grow room is arguably one of the most important decisions you will make when setting up your space. Lighting directly affects plant growth, flower development, yields, plant quality, and overall grow room efficiency, so choosing the right grow light is critical for achieving premium hydroponic results.

Today, full spectrum LED grow lights have become the preferred lighting solution for serious hydroponic growers due to their incredible efficiency, powerful light output, advanced spectrum control, and long-term reliability.

High-quality full spectrum LED grow lights provide plants with the complete light spectrum needed for every stage of growth, from seedlings and vegetative growth through to heavy flowering and final maturation. Unlike older lighting technologies, full spectrum LEDs allow growers to run a single fixture throughout the entire grow cycle without needing to swap globes or adjust lighting types.

One of the biggest advantages of modern LED grow lights is their energy efficiency. Premium LED fixtures convert the majority of power directly into usable light energy rather than excess heat, making it much easier to maintain stable grow room temperatures and environmental conditions. Lower heat output also helps reduce plant stress while improving grow room efficiency and reducing power consumption.

Another major benefit of full spectrum LED grow lights is their longevity and consistency. Quality LED fixtures can maintain strong light output for many years while delivering consistent plant performance, strong growth rates, improved flower production, and premium-quality yields.

As LED technology has advanced, modern hydroponic LED grow lights now offer growers exceptional results across all types of hydroponic systems and indoor growing environments. For growers chasing maximum yields, improved efficiency, stronger plant growth, and superior flower quality, full spectrum LED lighting is now considered one of the best investments for any hydroponic setup.