Growing Cannabis Indoors

Posted 7 years ago by Ian Shutts

General Guidelines for Growing Cannabis Indoors.

Growing cannabis indoors is different from growing cannabis outdoors in many respects. Here we will try and explain how to achieve a successful indoor grow.

There are three main objectives for opting to grow cannabis indoors. One is being covert. The second, to be able to fully control the environment. The third is to take things to a whole new level regarding productivity.

If you do not need to be covert, you would be better off growing in a greenhouse and save yourself some electricity.

Nevertheless, the same principles apply when it comes to growing cannabis indoors. Let us break down a little further.

When you choose to grow indoors, you will be limited by the physical space you have to work with. Some will be closet growers, others will build little micro greenhouses out of old adapted desktop computers. Others might retrofit an entire room for the purpose. The standard ready-made setup kits consist of a 1.2 x 1.2m tent that is 1.8m to 2m high.

As stated, safety needs to be your top concern. And the most telltale sign you are growing cannabis is the smell. Never underestimate the power of a female flowering plant! If left untreated, that smell can travel through multiple doors, multiple floors and even multiple blocks! And this is no joke. The best thing you can do is to buy an exhaust fan and a carbon filter to scrub the smell. This will double and an air replenisher. As plants grow, they consume CO2 and release O2. Carbon Dioxide is one of the main plant growth boosters. Advanced growers will run sealed rooms with CO2 tanks to increase the ppm count up to 1,500. Normal ambient Carbon Dioxide is about 350 – 400 ppm. This alone can massively increase yields but requires a very advanced setup.

But, we are getting ahead of ourselves here. Let us get back to some basics of growing cannabis indoors.

The Basics

As an absolute minimum requirement to growing cannabis indoors, is

– A properly defined space to grow
– Good exhaust port, an exhaust fan and tubing, and a carbon filter
– Pots and medium (soil, coco, hydro, rock wool, mapito)
– Nutrient and pH pen
– A light and a timer
– A cannabis clone or seeds

A properly defined space to grow is essential. It is going to make a bit of a mess. Do try to keep it clean. It will highly reduce the chances of bug infestation or dust getting stuck to your bud. It will avoid thing falling over and snapping your beloved plant in two. You would be amazed at how easy and often this happens.

This space should be isolated, either with a grow tent, of a cupboard, or a DIY secret room. The point here is to have the exhaust fan pumping air out of the room. This will create negative pressure. As air is pumped out, new air is forced in.

This is crucial for the two mentioned before. Because you attach a carbon filter to the intake of the exhaust fan, you will be forcing all the air containing cannabis sell out through it. This negative pressure going into the carbon filter will be both your best plant booster and your best insurance policy.

Regarding the pot itself, general rule of thumb is, the bigger the pot, the bigger the plant. Standard sizes for indoors vary significantly. If growing in a regular sized tent, aim for 12L to 16L containers. Depending on your skills level and techniques employed, this size pot can produce record-breaking yields.

The choice of medium is another long subject we do not have time to explore here. Chances are, if you are reading this, you are giving your first steps in the growing game. If that is the case, please quality brands specific for cannabis. That will rule out 90% of any potential problems you may face.

Our advice for growing cannabis indoors is to start off using organic nutrients, as these have a huge tolerance for errors before you truly understand plant nutrition and feeding regimes. Here is a misconception that using organics indoors does not produce the same yields and hydro or chemical fertilizers. This is simply not true. The fact is that for intermediate level growers, organics is tougher to dial in for extreme results. The main reason is, it is excruciatingly risky and complex to run large-scale automated grow rooms using organic fertilizers. But, if you are just running a couple of plants, nothing comes close to well grown organic weed.

And whatever you read, if you want to grow excellent looking plants, always use a pH pen to monitor the acidity or alkalinity of your water. The types and amounts of nutrients the cannabis plant can take is in direct relation to the water’s pH.

Light and Timers

Technology has come a very long way since the advent of indoor marijuana growing. Quite literally, someone thought up the brilliant idea of bringing in a street lamp into his house to pretend it was the sun. These are still in use today, they are called High-Pressure Sodium (HPS) bulbs or Metal Halide (MH) – and come in a variety of wattages, typically – 250w, 400, 600, 1000 w. They will also produce a lot of heat! Another reason to use a good exhaust system – to pump the excess heat out.

There are other options and newer technologies. You can use CFL lamps, Plasma and LED. They all have pros and cons – and prices vary tremendously. If you live in a cold climate, then MH and HPS are a plus if you live in a hot place, then LED are great.

Cannabis has two distinct phases – the vegetative phase and the flowering phase. The vegetative phases need 18h lights on, and 6h lights off – some growers prefer 20-on and 4-off. We will let you decide which is best.

The second phase is the flowering phase. You will see the 12/12 mark everywhere, though some growers swear by 11-on 13-off.

In any case, you light time is what is going to do all the hard work for you, turning the light on and off every day.

Clones or Seeds

Good quality clones are not easy to find. If you do find them, great! They will save time and you will only have one or two phenotypes to deal with.

Clones are almost impossible to find in Europe as growing cannabis is still frowned upon, but seeds are readily available worldwide. In most countries, under the pretext that it is for collection purpose only, you will not be breaking the law – do not take our word for it and check your local laws. Once you are confident there is no major problem, just order some online under a fake name if you prefer. Regular mail delivery you will not need to be signed for, and a little mailbox sized inconspicuous package will present itself in a week or two.

From here, it is just a matter of germinating the seed, and you are set to go! So what are you waiting for? A typical seed to harvest cycle is about 4 months long, you will have plenty of time to learn more as you go along. So let’s get moving!