Starting and running an indoor marijuana grow room might sound simple and easy. But when you get into it, you usually run into a series of issues that only time, investigation and persistence can solve.

This article details the experience of a novice cannabis grower who met one of this magazine’s team members and desperately asked for help after a couple of years of trial and error.

The novice grower had grown marijuana outdoors but never indoors. He thought all he had to do was buy quality seeds or clones, get a few buckets, fill them with quality soil, get some nutrients that worked well in soil, get a grow light, give the plants water, light and food, and within a few months he’d be harvesting stacks of buds.

But that’s not what happened. This article summarizes some of his mistakes and discoveries so you can avoid problems in your own grow room…

The first thing he discovered is he should have installed a mini-split air conditioner in his grow room. Without one, he found it impossible to keep the grow room in the proper temperature and humidity range using the whole-house air conditioner or by opening windows.

After two complete seasons in which excess heat and either too much or too little humidity harmed his plants and harvest success, he had a mini-split installed and it solved almost all his climate control problems.

Another mistake he made was buying a 1000-watt HID grow light. It was way too hot and intense for the square feet and vertical height of his grow area. He only wanted to grow 2-4 plants, or a small sea of green, and he had a slightly lower ceiling than most growers do.

The grow light burned his plants, wasted electricity, and jacked up the air conditioning bills. He ended up having to buy a 600-watt LED.

Yet another issue arose because he thought he could get away with using tap water or rainwater instead of spending money on a reverse osmosis (RO) filtration unit.

Most forms of unfiltered water contain unacceptably high levels of minerals and/or other contaminants that are bad for cannabis plants and can also sabotage hydroponic feeding programs and/or root zone pH. Reverse osmosis removes all materials from the feed water, giving the grower a pure foundation to dose nutrients into.

Reverse osmosis filtration works best when the whole-house water is pre-filtered using a water softener. Installing RO by itself may reduce water contamination to the zero parts per million ideal for marijuana watering, but without whole-house water filtration, the RO unit has to work ten times as hard. You have to replace expensive filters way too frequently, and much water is wasted.

The novice grower ended up getting whole-house and RO filtration. The side benefit is that whole-house water filtration gets rid of chlorine, minerals and other contaminants that harm people, plumbing and appliances such as water heaters.

The new grower also erred in his selection of nutrients. He kind of set himself up for this error by choosing to grow in unamended soil. It’s hard to find nutrients that work well in soil because soil may have chemical and physical properties that interfere with nutrients absorption.

Peat-based soil mixes have problems because peat tends to pack down, compress and waterlog, especially if the grower is overwatering.

The grower made it through two seasons with soil, but gave up on soil after discovering the soil contained mites. He switched to coco coir after carefully researching coco coir and nutrients. He chose premium coco coir and hydroponics nutrients, and his grow op problems associated with nutrients and root zone defects have receded.

Another problem for the new grower is familiar to most of us: bloom phase plant stretch that goes too far.

The novice grower let his plants stay too long and get too tall in grow phase. He didn’t realize that some strains, especially Sativa strains, may double or triple in height during bloom phase. Coupled with the problem of a rather low ceiling and the searing HID grow light bulb, he had to tie his plants at a horizontal angle to keep them out of harm’s way.

Even after he replaced the HID grow light with the LED grow light, he still made the mistake of letting his grow phase plants get too tall. He now has made marks on the wall of his grow room indicating the maximum height for grow phase plants for Sativa and Indica strains.

The marks were made after measuring his plants’ bloom phase growth spurt and then adding a few inches on to that,  just to be safe. Now he flips his plants into bloom phase when they’re 20-24 inches high max, depending on the strain’s likely bloom phase stretch, and has eliminated the problem of too-tall plants that get too close to grow lights.

One of the strangest problems he created for himself was in being too aggressive in repeatedly topping his plants. He didn’t know that topping plants often delays flowering onset. Nor did he anticipate how his plants would double or triple in girth due to topping.

He was growing in 5-gallon pots, and his topped plants put forth multiple double shoots and side branches. He had plants with a massive canopy two to three feet or more in diameter, growing in pots that were way too small for them.

Starting in peak bloom when the buds got heavier, the plants started leaning one way or another. They were unstable, and some fell over on their side.

He found that the 5-gallon pot size wasn’t big enough to put sufficient stakes into the pots to stabilize the plants. He didn’t want to create plant stress by repotting the plants into larger containers, so he piled up construction bricks on the sides of the pots to stabilize them.

It didn’t work, so he got smaller bricks and put them IN the pots to add weight to the root ball to balance the top-weight. This tactic kept the plants from falling over, but also crushed the root zone, leading to waterlogging, lack of oxygen in the root zone, and damaged roots.

Yet another mistake the novice grower made was when he procured clones from a fellow grower but failed to closely inspect them before purchase.

The clones had a very tiny infestation of spider mites. The grower made the further mistake of not paying close enough attention to his cannabis leaves as the plants grew. If he had, he’d have noticed the tiny stippling marks on the top of leaves, created by spider mites on the underside.

Only when the plants were in early bloom phase did he see the mites’ web tents, look the problem up on the internet to identify the problem, and take action. Unfortunately, the action he took was to spray a toxic pesticide on his plants. It damaged his plants, and left a residue on the buds that made them very harsh, with a bad taste. He later learned that the pesticide is poisonous when combusted.

The grower abandoned clones and ordered seeds from an overseas seed bank. He made two mistakes doing that. He didn’t research the seed breeder or the strains he was ordering, he just trusted the strain names. He didn’t research the seed seller either.

Many of the seeds he received didn’t germinate. The seeds were advertised as feminized, but some of them grew out to be male. The plants didn’t look like the strains he had ordered. The high and yields were disappointing. The seed seller refused to give him any kind of compensation. What he should have done is order from a reliable seed breeder and seller, such as New420Guy Seeds.

As you see, there are a ton of mistakes marijuana growers make. You can read the best marijuana growing books and watch the best marijuana growing videos, and it will help you avoid cannabis growing errors.

But only by experience will you eventually learn all the dos and don’ts of marijuana growing to the point where you no longer make these common mistakes.

Now that you’ve read this article, you’ve seen some of the most common mistakes made by marijuana growers, and you can avoid them.

As we put this article together, we realized there are dozens more marijuana growing mistakes, some minor and some catastrophic, that we don’t have the room to list right now.

So look for our next article on avoiding common marijuana growing mistakes, and be very careful in your grow room. Unforced errors are the most prevalent cause of grow room failure. The more aware and careful you are, the more likely you are to harvest stacks of big, fat, sticky buds every cannabis growing season.