Indoor marijuana growing

Tips and advices for a successful indoor cannabis crop.

Tips to avoid stretching cannabis plants

What is the stretch?

Stretching at the onset of flower

This cannabis plant is just beginning to stretch

Stretching is what we canna-cultivators call the natural vertical growth spurt put on by cannabis plants during the early stages of flowering, and more notable in Sativa varieties and Sativa/Indica hybrids. Most varieties that display this characteristic will finish stretching by the third or fourth week of 12/12 photoperiod and start to fill out the bud sites, while some strains can continue stretching for a considerably longer time.

Stretching is largely looked upon as something to be avoided at all costs when growing cannabis. This is due to the multitude of problems that can be caused by a grow room full of tall and spindly plants, reducing production as plants outgrow the cultivation area and reach up into the lights, shading lower bud sites and causing weak, airy bud growth. In other words, spoiling all our carefully laid plans for keeping an even canopy throughout the flowering period and definitely not maximising the efficiency of our grow space or lamps. Continue reading

Rooting clones with Green House Feeding Bio Enhancer

As some of you may know, we’ve recently added the new Green House Feeding Bio range of nutrients for plants to our catalogue, which is composed of three excellent products. On the one hand, we have two completely organic base nutrients in powder form, one for the growth phase (Powder Feeding BioGrow) and another one for the bloom stage (Powder Feeding BioBloom). On the other hand, we have a highly efficient root stimulator called Additive Feeding Enhancer, which we’ll test in this article.

GH Feeding Enhancer is a complete mix of humic acid (75%), fulvic acid (3%), seaweed extract (10%, Ascophyllum nodosum), Trichoderma harzianum (10%), Bacillus subtilis, alginic acid, manitol, fucoidan and several amino acids (alanine, aspartic acid, glutamic acid, glycine, isoleucine, leucine, lysine, methionine, phenylamine, proline, tyrosine, valine and tryptophan). This complex provides the root system of your plants with all the necessary elements for explosive growth, plus extra protection against several phytopathogens that may harm the root ball. Furthermore, it also enhances nutrient uptake while stimulaitng microbial life, improving the vitality and resistance of plants against adverse conditions.

Green House Feeding Bio

Green House Feeding Bio

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How to grow cannabis plants in clay pebbles

Growing with clay pebbles

Expanded clay pebbles are a widely used growing medium in the world of hydroponic cultivation. It’s a lightweight, roughly spherical, red ceramic aggregate with a high iron content. Before it can be used, it must undergo several different processes during manufacture. The most important of these steps is heating at extremely high temperatures, causing the rapid expansion of the clay and trapping air in pores within the odd-shaped balls. Clay pebbles have many uses besides hydroponic growing, also being widely used in construction as lightweight aggregate and thermal insulation, etc.

The size of clay pebbles can vary from 5 mm for the smallest to 15mm for the very largest kind. It must be noted that bigger clay pebbles will retain moisture  more easily and for a longer time than those of smaller size.
In this post we will focus on explaining how to properly employ clay pebbles in cannabis cultivation and avoid any potential problems using this hydroponic culture medium.

Buds grown in clay pebbles

Buds grown in clay pebbles

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How to grow cannabis plants in coco coir

Coco coir as substrate for plants

In this post we’ll explain how to properly use coco coir as a substrate for our cannabis plants. After years of experience with this growing medium, we believe that coco coir is the easiest choice among hydroponic substrates.

To get the most out of it, first of all we should take a closer look at its composition and properties.

Coco fibres for hydroponics

Coco coir for hydroponic cultivation

Coco coir is an organic product that comes from the fruits of coconut trees. After processing the coconuts, the remaining fibres of the husk or mesocarp are collected as waste material. These residual fibers are in the form of powder and filaments, and the mixture of both is an ideal substrate for ornamental plants or intensive hydroponic cultivation.

If we take into account the advantages of coco coir when compared to soil, we’ll soon understand why so many growers are considering growing their plants in coco. It’s important to highlight the differences between coco coir and other substrates to understand the great results obtained with this growing medium.
Firstly, it should be stressed that coco coir is an inert substrate. This means that it doesn’t contain nutrients, so we must fertilise whenever we water the plants.

The aeration capacity of coco coir is one of this substrate’s strong points. It’s an extremely soft growing medium, which enables the root system of the plants to develop much faster than in soil. A stronger root ball means more vigorous growth, which allows a reduction in the vegetative period. Also worth mentioning is that coco coir contains natural Trichoderma, beneficial fungi which enhances the development of roots and improves the plant’s immune system, creating a colony of microbial life that greatly enhances the metabolic processes of the plant.
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Vapor pressure deficit (VPD) in cannabis cultivation

What is vapor pressure deficit?

Often, marijuana growers who have their plants in indoor grow tents or rooms with artificial lighting, take into account parameters such as temperature and relative humidity to maximize plants growth and bloom, thus obtaining abundant harvest with top quality flowers. As we will see later, these factors affect different processes of the plant, such as transpiration or nutrient uptake.

However, we usually forget about another important factor that is related to the aforementioned ones: vapor pressure deficit or VPD. Broadly speaking, VPD is the difference between the amount of water vapor that the atmosphere is able to retain (which depends on temperature) and the amount of water vapor contained in it (relative humidity). It is usually measured in kilopascals (kPa).

Dew is formed when the environment is saturated with water vapor

Dew is formed when the environment is saturated with water vapor

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The effect of cold on cannabis plants

Cannabis as a plant species grows wild in many places of our planet Earth. As a result, we can find a great diversity of cannabis genetics worldwide. Across the different regions where these plants are found, there are significant environmental and geographical differences in altitude, latitude, temperatures, humidity, photoperiod, etc.

Cold, warm and hot areas of the planet

Cold, warm and hot areas of the planet

In countries closer to the tropics where cold weather is rarely experienced, it’s possible to cultivate cannabis throughout the whole year, and the Sativa or NLD (Narrow Leaf Drug) varieties that are native to this tropical region are adapted to cope with a relatively stable climate without great variations in temperature or photoperiod. As we move further away from the equator, to countries such as Pakistan, Lebanon, Afghanistan, India, Russia, China etc, weather conditions become more diverse, with clearly defined seasons and as a result, the period in which it is possible to cultivate cannabis is shortened according to latitude. The plants native to these areas are known as Indica or WLD (Wide Leaf Drug) varieties and they are well equipped to deal with wide variations in climactic conditions affecting temperature, humidity and also the effect of the changing photoperiod on plant morphology and life cycle.

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Growing cannabis in Rockwool

How to grow  in Rockwool

  1. History of Rockwool
  2. How to stabilise Rockwool
  3. How to germinate seeds in Rockwool
  4. How to root cuttings in Rockwool
  5. How to grow in Rockwool
  6. Recycling Rockwool

1. History of Rockwool

Eruption of a volcano in Hawaii

Eruption of a volcano in Hawaii

Rockwool is a product that was first conceived during the 20th century in Hawaii by observing natural volcanic action there. Upon this discovery, a Danish company named Rockwool began to investigate and develop ways to commercialise this technique, and in the late 1930’s released the first standardised stone wool product as we know it today.

To manufacture Rockwool, the raw material of basalt rock must go through several industrial processes, the first of which is melting of the rock in furnaces at extreme temperatures, up to 1600ºC, emulating the action of a volcano and leaving the rock in a natural state of liquid lava.

To obtain the fibres, an organic binder is added to the lava and the mixture is subjected to a mechanical process using centrifugal force, resulting in something resembling a woollen mattress. This wool is then compressed to varying degrees, the density and amount of air between the fibres depending on the projected end use, whether for acoustic or thermal insulation, fire-protection and, of course for it’s use in agriculture.
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How to set up a magnetic ballast

How to install a magnetic ballast?

Today, we can find on the market a considerable number of ballasts or power supply units for indoor gardening. Most of them – for example, electronic ballasts – are easy to install since they don’t require prior manipulation from the user.

250W ETI magnetic ballast

250W ETI magnetic ballast

But what happens with magnetic ballasts? These sometimes may require some type of installation prior to their use.

On this article we’ll show you how to install a 250W ETI magnetic ballast easily and safely. In this way, you’ll have no problems when setting up the lighting system of your indoor grow room.

Magnetic ballasts are very easy to install. We only need a flathead screwdriver  to connect the cables to the ballast’s terminal strips. 

Normally, all magnetic ballasts have an assembly plan printed on them to check how to connect the cables. But, in order to avoid confusions, we are going to tell you step by step how to install it. It only takes  2 minutes and you’ll make sure that you’re installing the ballast properly.

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Ballasts for growing cannabis plants

Ballasts and growing cannabis plants indoors

When we are about to set upe an indoor marijuana growing space, there are many factors to take into account if we want our plants to enjoy proper ventilation, lighting, etc. If we grow with discharge lamps (HPS or MH) we are going to need a ballast to correctly operate our lighting system.

The main doubt that can arise is whether to choose a magnetic or an electronic ballast. Electronic ballasts are a step forward in lighting systems for growing cannabis, replacing the traditional power transformer of the magnetic ballasts with electronic components.

Although the price of most electronic ballasts is a little higher than that of magnetic ones, they have a number of advantages in comparison with these:

  • Electronic ballasts are lightweight, smaller and they practically don’t emit heat
  • They’re much more efficient, with a better use of the electrical consumption
  • They are more silent, compared to the vibration emitted by magnetic ballasts
  • They lengthen the lifespan of the lamps and reduce flickering
  • Most of them have dimmers that allow us to control the light output according to the needs of our plants
HPS and HM lamps need a ballast to operate

HPS and HM lamps need a ballast to operate

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Electrical conductivity and cannabis

What is EC or electrical conductivity ?

In this post we look at the concept of EC or electrical conductivity with regard to cannabis growing and explain its importance to obtain good results in our crops.

Reverse Osmosis System

Reverse Osmosis System

EC is the measure of the ability of a fluid or material to conduct electricity. The water, through which the plants feed, contains dissolved minerals called aqueous solutions. These aqueous solutions can contain more or less mineral elements (salts), which directly determine EC levels.

The water itself is not conductive: RO water or distilled water have an EC value=0, which means that it won’t carry electricity. We must add and dissolve mineral salts to make this water conductive. We can add these salts in the form of organic or mineral nutrients.

Reverse osmosis filters clean the water from impurities, so the water obtained have an EC value around zero. These devices are mostly used by those growers who have water with high initial EC levels (hard water), above 0.6. If this is the case, use a mixture of tap water and RO water to obtain an initial EC level of around 0.4 points. Adjusting the EC value of the RO water with calcium and magnesium is also recommended, using one part of magnesium for every two parts of calcium and raising the EC value from 0.0 to 0.4. From this point on, start adding fertilisers to achieve the desired EC level.

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