Mold Testing of Marijuana Grow Houses in California

Mold Inspection of Marijuana Grow Houses in California

Mold Inspection of Marijuana Grow Houses in the California Region

Marijuana grow houses across California are liable to be taken over by mold and mildew due to the growing conditions that marijuana favors. However, the presence of marijuana is also detrimental to the residents of these buildings. Hence, the need to test and inspect grow houses for molds while marijuana is growing, and before they're listed for sale or lease, as stipulated by the Californian government.

A mold inspection of marijuana grow houses in California shows the suitability of grow houses for people, whether they're working in the structure or living in a part of it. It also shows the suitability of grow houses for the optimal development of marijuana and its influence on the health of the inhabitants.

Growth Conditions for Marijuana in Grow Houses

Marijuana, since its legalization in California, has been grown both indoors and outdoors by both licensed growers and some illegal growers. The outdoor conditions for growing marijuana in California can be unstable, and that adversely affects the output of many growers. However, with indoor marijuana cultivation, usually, in grow houses, growers can control the temperature, humidity, and light that is available to the marijuana plant. They can easily manipulate these growing conditions to determine their plants' yields.

Cannabis mold testing California

Mold Testing Marijuana Grow House California

The growth conditions for marijuana in grow houses, which increase growers' yields include:


The heat of a grow house affects how well and strong the marijuana plants grow. Your light source, outdoor temperature, airflow, and plant metabolism contribute to how much temperature your marijuana plants will need in grow houses. However, you can control these influential temperature factors regardless of the outdoor temperature.

Marijuana requires different temperature ranges at different growth stages;

• 75 to 85°F for the seedling stage
• 70 to 85°F for the vegetative growth phase
• 65 to 80°F for the flowering phase

Humidity also plays an important role in the temperature of your grow house.


Together with temperature, humidity is an important factor in the growth and well-being of your marijuana plants. It determines how much moisture you have in your grow house, and marijuana can be sensitive to moisture. If the outdoor humidity is high, you'll have a low chance of keeping your grow house dry for your marijuana plants.

For their different growth phases, marijuana needs approximately 70%, 50%, and 45% of relative humidity in their seedling, vegetative, and flowering growth phases, respectively.


Photoperiod, that is light duration, influences the growth phases of marijuana plants and the temperature of your grow house. There are many light options for a grow house. However, the T5 fluorescent light bulbs are common among small-scale cannabis growers. High-intensity discharge lights are the go-to options for bigger marijuana growers; however, they emit a substantial amount of heat.

During the vegetative phase of marijuana growth, 18 hours of light is needed. However, the flowering phase needs 12 hours of light.


Ventilation is important in controlling the temperature and humidity in your grow house. Although you can use fans and air conditioning systems to ventilate your grow house, open spaces have the best air circulation. High humidity and temperatures cause the build-up of pathogens and other organic materials, such as mold and mildew, in your grow house.

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Mold and Mildew Growth in Marijuana Grow House

One of the biggest problems a marijuana grower can face is the growth of mold and mildew in his grow house. This can spread quickly and will soon take over the plants and other plant materials in the grow house, causing a capital loss for the grower.

Mold is a fungus that feeds on plant materials and thrives in a moist and humid environment. Usually, its optimal growing condition is relative humidity below 60%. Since the relative humidity of a grow house for marijuana at all of its growth stages can easily be at 60%, your grow house can be a good breeding ground for mold and mildew.

Consequences of Mold Growth in Marijuana Grow Houses

When the humidity in a grow house is too high, and air circulation low, especially in smaller grow spaces for marijuana, such as shelves and room corners, there's an increased chance of encouraging mold growth, and that comes with some potentially severe consequences for the integrity of the building structure.

Marijuana Loss

Mold is a fungus that survives on cellulose that it can easily find on plant matter. Marijuana is a good source of food for molds, hence, their growth and multiplication on marijuana plants. Mold can easily spread and take over the grow house and consume all the plants in that space if left unchecked.

Monetary Loss

The loss of your marijuana plants equates to monetary loss if you're growing cannabis for commercial reasons. Growing marijuana indoors requires more capital investment than doing so outdoors. That means you incur greater losses if molds take over your grow house.

Health Concerns for Residents

While money may be made after some time, you can only do so when you're in a good health state. Exposing yourself to molds may be detrimental to your health.

Limited exposure to mold spores may cause mild allergic reactions such as rashes, sneezing, nasal blockage, and watery eyes. However, extended or daily exposure, especially to toxic molds, can lead to more serious health concerns such as sinus problems, neurological issues, and even death.

Also, consuming marijuana with mold growth may expose you to mycotoxins such as aflatoxin.

Mold Inspection Marijuana Grow Houses in California

Mold Inspection of Marijuana Grow Houses in California

Destruction of the House Structure

Molds reproduce rapidly and can take over a whole building in months as long as there's sufficient food. In a marijuana grow house, all growing and reproductive conditions are available, hence, they'll quickly spread from the dark corners to the ceiling, and every part of the house with plant materials, such as drywall, doors, and roof.

When they reach the recesses of the grow house, they begin to compromise the strength of the supporting beams, causing the house to become weak as time goes by.

Prevention of Mold Growth in Marijuana Grow Houses

The best remedy to mold growth is prevention, and that involves consciously controlling the growing conditions in your grow house to reduce the potential for mold growth. You can achieve this by:

Humidity Control

Control the level of atmospheric moisture in your grow house to always be below 60% in their vegetative and reproductive growth phases. During their seedling growth phase, you should ensure that there are no dark corners, and when the lights are out, ensure maximum air circulation.

You can use dehumidifiers to reduce the level of humidity in your grow house. Fans and AC will also help with air circulation.

Spacious Planting Distance

Practice sufficient plant spacing to encourage air circulation and discourage the easy spread of mold. Good plant spacing also allows more light penetration and removes shadows from every area.

You can also use the separation planting technique, where you have separate units of marijuana plant clusters. This limits the possibility of mold growth and reduces your losses if it does happen.

Regular Mold Inspection

You can't be too careful with molds in a grow house. They can pop up in any corner and remain there waiting for the right conditions to reproduce. Therefore, you need to be on a constant watch for them.

You can prevent a mold outbreak in your grow house by discovering them on time. Schedule a monthly mold inspection with a mold testing outfit in California. Also, if you've been growing marijuana in your house, and you're looking to leave, you're required by law to test your house for molds, hence the need for a mold testing agency.

The necessity for Mold Inspection of Marijuana Grow Houses in California

With many licensed marijuana growers in California opting for growing cannabis in buildings, there is a high chance of mold growth. This is why the Californian local government has mandated that every house should be tested for molds before they are sold or leased. Here are some reasons you should inspect your grow house for mold.

Avoid Marijuana Plant Loss

Earlier detection of molds can save your marijuana plants from getting lost to the fungus colony as they multiply. Regular mold testing is the best way to detect the presence of mold or mildew early.

Avoid Financial Loss

Scheduling monthly mold inspection for your grow house greatly reduces the chances of losing your capital to mold infestation. Mold inspection tells you about their presence while treatment against molds eliminates them before they can spread to your plants and prevents major financial losses.

Eliminate Health Concerns for People

Molds pose great health concerns to humans, whether their spores are inhaled or ingested. You need a regular mold inspection and testing to be sure they're not present in your grow house, as they can cause allergies, respiratory issues, and even death.

Ensure the Habitability of the House

If you decide to move on from that grow house, and you're thinking of putting it up for lease or sale, you're required, by law, to test that house for mold, and ensure its livable for humans.

Mold inspection and testing will determine if there has been any mold growth. If any of these tests are positive, it’s possible there may have been structural damage to the house and there will be spores that may cause health problems for subsequent house inhabitants.

Final Thoughts

Your marijuana plants and molds have some similar growing conditions, and mold growth is detrimental to your success as a marijuana grower.

Whether you're a licensed or unlawful marijuana grower in California, your grow house should have regular and frequent mold inspections whether you're still growing cannabis in that house or you're looking to move away from it. It assures the government that it is a suitable environment for future residents. Contact us for your quick and affordable mold inspection and testing.