Frequently Asked Questions about Hydroponics - 2020

Frequently Asked Questions about Hydroponics - 2020

What EC should I maintain in hydroponics?

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.

EC is the measurement of food present in a hydroponic nutrient solution, without an EC meter or ppm truncheon you are essentially growing blind, visit your local hydroponic shop or buy one online from your regular hydroponic retailer.


Growth/Vegetative requirements: 0.6 - 0.8 EC


Bloom/Flowering requirements: 1.6 - 2.4 EC


What pH should I maintain in a hydroponics system?

The consensus for pH in a hydroponic system & coco coir is that it should be kept between 5.5 - 6.5 throughout cycle, ideally in the growth/vegetative phase pH should be maintained at 5.8-6.2  - if the pH fluctuates too much the plant will be unable to uptake specific "slow" moving nutrients which can cause nutrient deficiencies, so having all the necessary equipment like pH meters will save a lot of guesswork.


When the plants go into the flowering phase consistency is key ensuring the plant has a constant availability to the hydroponic nutrients it requires, the preferred ph range in flower is 6.0 - 6.4 as different quantities of specific nutrients are required in the bloom phase, if this ph range was lower or higher the plant would be unable to absorb targeted and much needed plant nutrients, thus stifling development and potentially impacting the end result which in most cases is a reduced yield. To get the best yield always check the pH of each hydroponic nutrient mix before feeding plants. In a recirculating hydroponic system you’ll need to do daily reservoir checks to ensure the pH is correct, if it isn’t you can use pH down or pH up to adjust your nutrient solution.


Should I use EC & pH meters for hydroponics?

Operating a hydroponics system without these meters is very difficult and it would be very hard to achieve optimum results. Always use meters to attain perfection. Otherwise you’re just guessing. Visit your local hydro shop and get more info, if you don’t have a hydroponics retailer close by speak to a local gardening shop to see if they can order one for you.


How long should I run my LED grow lights?

The general rule of thumb for vegetating plants is 18 hours of light and 6 hours of darkness, once flowering has begun or the plant is of suitable size to flower you will need to change your photoperiod to 12 hours on and 12 hours off, keeping in mind that once your plants start flowering the darkness cannot be interrupted, if light enters the space when flowering, you could reset the plant to vegetate or even worse, they can stress out which will massively impact the end result and in some cases cause Hermaphrodites.


How do I measure my hydroponic grow light?

You can measure your HID or LED grow lighting using a quantum meter, these meters measure the light that reaches plant canopy per second (ppfd) and they also calculate the daily accumulated light (DLI) required which is measured in moles. There is a requirement of light needed in the vegetative stage and a different need for the flowering stage of a plants life cycle, understanding these differences will help you grow better. Check out ppfd guide for specific plant requirements, as there are many differences between crops.


Does the hydroponic nutrient solution need to be heated?

In Winter in Australia hydroponic heating is absolutely necessary. It is best to maintain your hydroponic nutrient solution between 18.5 - 26 degrees (C)

If the grow room and hydroponic nutrient temperature falls below 15 degrees during the dark period (lights off), then you will require a water heater. If the nutrient solution does goes below 15 degrees the plant will stop up taking nutrients as the plants metabolism shuts down at this temperature.


Does the hydroponic nutrient solution need to be Cooled?

In the warmer months, like spring and summer in Australia if you are not in a temperature controlled growing environment then yes.


If the solution rises above 26.5 degrees it can become the perfect breeding ground for algae, Pythium and a host of other bacterial infections, so try to stay within temperature range. The pH of the nutrient solution will also change when the temperature rises.


What causes plants in grow rooms to die?

There can be a number of reasons for this. Firstly, eliminate the obvious things like lack of water, faulty hydroponic lighting, high temperature and plant health in general.


Root diseases are the most common cause of "sudden death" for plants and can cause many problems from loss of yield to complete death. Pythium is the most common root disease as it is carried on the feet of an insect called the fungus gnat which is quite a common bug issue for indoor gardeners.. Ignoring the basics on temperature and humidity control can present quite a nightmare. Always use hydroponic nutrient conditioners if your reservoir or hydroponic nutrient tank is prone to temperature rises, these formulations mostly contain chlorides, hypochlorous acid, quaternary ammonium and copper which will help prevent nasty pathogens from taking hold. If you are still unsure after checking these parameters google hydroponic shops near me and visit your local hydroponic retailer for further insight to your plant or grow room problem.


What causes the tips of the plants to burn?

This can be caused by too much plant food being added to the reservoir/water tank, as the nutrient accumulates there can be a compounding effect as the food is not taken by the plant the concentration of food increases only causing more issues, flushing regularly with plain pH water will slowly fix this issue. Once the EC range is low enough the plant will start consuming hydroponic fertilizer again.


Good quality hydroponic nutrients that are approved for use in consumable crops will generally state this on the label, if the nutrient doesn’t have APVMA approval steer clear as these nutrients could contain harmful chemicals like PGRs not disclosed in the ingredients list.


There are some nutrient deficiencies that can also cause leaf tip burn. If you have a pH and EC meter this is rarely posed as an issue as you’ll be well aware of any changes to your hydroponic nutrients.


What causes plant leaves to turn yellow?

This can be caused by a number of factors:

  • Low CO2 Levels
  • Nutrient deficiency
  • Grow room leaching chemicals into plants
  • The pH is too high/low.
  • Hydroponic grow lights too close
  • The hydroponic nutrient solution is too hot/cold.
  • Too much nutrient build up in the water.


All of these issues prevent the plant from absorbing nutrients in the correct quantities, always use an EC meter and a pH pen to prevent this from happening. If you don’t have one jump online and check out your closest hydroponic retail shop by searching for hydroponic shops near me. You should be able to buy all of the co2 bags, hydroponic nutrients and hydroponic equipment to remedy these problems.


Why do plants stretch indoors?

Plants stretch when the light is insufficient or humidity is too high, grow room environmental control and plant canopy airflow is key, if the environment has poor airflow this can cause bolting. Use a CO2 generator bag to increase the amount of Co2 in your grow room this will help your plants photosynthesise more of the grow light that you are using.


Plants stretch when the light is too far away from the plants or there may be too many plants competing with each other for the light, alternatively the light could be insufficient, speak to your hydroponics shop for more info.

If you have changed your photoperiod recently then the plant stretch is quite normal, most plants stretch 50-250% of the size they were usually in a 2-3 week period and then they will continue to swell and fill the space available to them, so always plan accordingly and try not to vegetate your plants too much past the 1-1.2m mark in height especially in a grow room that’s limited to 2m or less in height, again always visit your local hydro shop for more info.


What grow room humidity should I maintain?

Vegetating/growth: 60-65%

Flowering/bloom: 50-55%

Drying: 48-55%

Curing/storing: 55-62%


Excessive humidity for long periods will create undesirable conditions that are perfect for grey mould. Grey mould, once started, will quickly spread and affect your entire crop especially if your growing space is limited to a small grow tent or medium sized grow room.


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%, is perfect in the flowering cycle and should not go above this. It is important to keep hydroponic nutrient reservoirs covered at all times so that they do not evaporate and 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. As a general rule it is good to keep your grow rooms dry. This will prevent any mould problems.


What temperature should the grow room be?

Optimal room temperature is between 24.5 - 29 degrees in the vegetative phase.

Optimal room temperature is between 22.5 – 32.5 degrees in the Flowering phase.

Optimal room temperature is between 20 - 22.5 degrees in the Drying phase.


It is not that difficult to achieve this temperature range in your grow room, especially when the lights are on. In your warmer climates if your temps become too high, inlet & extractor fans pumping the hot air out of the room will control temps well.


You can set up a thermostat to your fan to automate things. When the lights are off you need to make sure that your temperatures do not become too low. Most of all you will want to avoid huge temperature fluctuations between the day and night cycles because this will make your plants poorly formed.


How much ventilation do I need in my grow room?

Ventilation needs to be enough to maintain a temperature of about 25- 28 degrees and a humidity of about 55-65%.


Generally it’s better to have too much than too little ventilation. As a rule of thumb, during summer give about 120 litres per second of air going in and the same amount being vented per square metre of floor area. You can calculate this by using the many CFM or CMH calculators online and make sure you have at least selected 3-10 air exchanges per minute or if you choose the hourly option a minimum of 180 air exchanges within that hour.


If ambient weather impacts your grow room try to maintain the temperature inside no higher than outside. In winter, vent according to ambient temperature and humidity. You will obviously need to employ hydroponic heating equipment to bring the growing temperature up.


What size reservoir should I use in my grow room?

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


The quick answer is use a minimum of 50-100 L litres per meter of grow room so for a 1.2sq a 50L reservoir will be enough if it’s a 1.2 x 2.4 style grow room you’ll definitely need to use 100L nutrient tank, less than this requires frequent adjustments and top ups, work smarter in this area as it is quite a time consuming task.


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 if you have many of them in your grow rooms.


Is it necessary to prune the leaves off plants?

The plant takes a long time to develop and grow its leaf sets, removing the larger ones can be detrimental to some types of plants. It takes a long time to grow those big leaves cutting them off will only be detrimental to the plants overall development.


Pruning has been confused with plant training so be careful about the information source before attempting a major haircut, once you have a full size plant you can then start to trim and train as the plant will have enough size to regenerate itself, check out the hydroponic blog and tutorials section on our website for the many different training methods you can try in your grow room.


Should I aerate the hydroponic nutrient solution?

Aerating the nutrient solution is a great idea. It guards against stale nutrient solution, improves plant health and prevents bacterial infections. Aerating your hydroponic nutrient solution will last far longer than one that is sitting flat. Unless you’re trying out the Kratky hydroponics method in which case no aeration is needed just many frequent nutrient solution changes. Aeration can be achieved using an air pump, the ones we sell in our hydroponics store come with all the airlines and air stones necessary to aerate you hydroponics nutrient tank, hydroponic system or nutrient reservoir.


How long should it take for clones to strike roots?

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 where cloning gels, root boosters and grow cubes are used. Genetics do play a part and some varieties can take much longer than others, some you could throw at a wall and they will root. Check out the A-Grade Hydroponics cloning guide online to improve your success rates if you’re struggling in this area.


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


What is the best water to use for growing plants?

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 which in Melbourne it is.


Most Australian tap water is valued between 0.0 - 0.3


Reverse osmosis is a preferred method as well, the only downside is pH fluctuations (using a hydroponic pH stabiliser solution will correct this) and the water after it is cleaned will require re-conditioning with a calcium magnesium additive. A lot of work in our opinion, the tap water in Australia is fine, if you’d prefer to remove the chloramine or chlorine additions that are used in water treatment you can buy these hydroponic water conditioners online or instore.


Hydroponic Grow Rooms - How to set up a hydroponic grow room for beginners?

An indoor hydroponic grow room can be set up just about anywhere, from a spare room to a garage or shed.


There are just a few things that you need to take into consideration when picking out the perfect place for your hydroponic grow room.


To get an idea of just what your plants will require, picture a sunny spot of an outside garden on a warm summer's day. Just about any plant will grow well in these conditions. And this is the same exact conditions that we need to recreate in an indoor hydroponic grow room. There are three major categories that we need to focus on in creating a grow room: temperature, humidity, light.


Hydroponic Grow Room Lighting which LED grow light should I buy?

If you had to choose one thing that was the most important in maintaining a hydroponic grow room it would be lighting. Now this will not matter much if you are in a greenhouse located outside, but if you are in a cellar or in a structure with a normal roof you will have to provide the light yourself and recreate light that is similar to the suns rays.


The good news is that with modern day horticulture, technology has created sun light that operates in an efficient and cost effective manner. In fact if you are choosing to set up a hydroponic grow room indoors it is best that you use only artificial lighting and do not bring light in through windows or skylights. Artificial lighting is easily controlled and provides the growers the ability to set the lights on timers to turn them on and off as needed.


By using artificial lighting the grower can simulate the long days of summer for high growth levels, and slowly start reducing the light to simulate fall and induce the plants to start flowering. A hydroponic grow room designed well will produce great results in almost any type of plant that you decide to grow.


Is it safe to run these type of grow lights in my home?

Yes, Indoor grow lights are very safe. LED grow lighting systems are used in all industries.

Systems that are compliant and tested to Australian lighting and electric standards help assure safe lighting fixtures.


Why should I use LED grow lights in my indoor grow room?

Quick answer, Yield and plant health. LED growing lights are the most intense source of full spectrum grow light available. They are also more efficient as a light source. They offer less thermal energy than the traditional lighting used to grow crops like HPS and MH but they emit far more light, so as long as you understand environmental temperatures, leaf surface temperature and canopy airflow you’ll love LED grow lights as you will achieve a higher light saturation which usually translates to the crop yield increasing. For more info on these check out the website or find your local hydroponics shop by searching for hydroponic shops near me or LED grow lighting.


When should I use T5 fluorescent grow lights?

Fluorescent T5 grow lights work best for seedlings, clones and to supply supplementary lighting in the early stages of a plants life cycle, they offer a tenth less of the light that’s needed for larger plants so they can only do so much. They are only utilised in the propagation stages of a plants life cycle. Always transition to a higher wattage LED grow light to achieve optimal results.


Which type of hydroponic grow light should I use?

The hydroponic indoor lighting industry has come leaps and bounds and is a whole newly innovated version of the old school lights we grew up using. HPS lighting is still available through some hydroponic suppliers so always check with your local hydroponics shop if that is your preference. The majority of indoor grow light kits now purchased fall under the category; full spectrum LED grow lights, you can find these lights under LED in our product menu. These lights are used as a start to finish solution for vegetating cycle and the bloom cycle.                                                                                                                                                                 




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