How to Properly Flush Cannabis

Cannabis plants are known to be pretty hardy, but that doesn’t mean they don’t need a little help every now and then. If you want to ensure your plants are getting the nutrients they need, it’s important to properly flush them before harvest.

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The Different Ways to Flush

There are many different ways to flush your cannabis plants, but the most common and recommended way is to use pure water for two weeks. This method is simple and effective, and it will remove most of the residual nutrients from your plants. However, there are a few other ways to flush your plants that you may not have considered. Let’s take a look at a few of them.

Flushing with Water

The most common and effective way to flush your cannabis plants is by using water. This method is also the gentlest on your plants, so if you are concerned about stressing them out, this is the way to go.

To flush with water, you will need to water your plants as usual, using twice as much water as you normally would. Allow the water to drain all the way through the soil and out the bottom of the pot. Once the water has stopped draining, wait a few minutes and then water your plants again. Repeat this process two more times.

After you have watered your plants three times, wait a few days and then check the soil. It should be light and fluffy, with a yellowish tint. If it is still dark and dense, flush again.

Flushing with Air

The final two weeks before harvest are vital to the success of your crop. This is when you flush your plants, which means giving them only water — no nutrients. The purpose of flushing is to remove any residual nutrients from the plant material so that they don’t end up in your final product. Flushing also helps to improve the flavor of your buds.

There are two main ways to flush cannabis plants: with water or with air. Many growers prefer to flush with water because it’s less work and you can see results more quickly. However, flushing with air is just as effective and can be done more easily in a smaller grow space.

To flush with air, you will need an oscillating fan and a mechanism to direct the airflow around your plants (such as a cardboard box or small tent). Turn on the fan and direct the airflow towards the bottom of the plant so that the fan will move the spent nutrient solution out of the pot and away from the roots. Continue this process for at least 12 hours a day for 7-10 days before harvest.

The Pros and Cons of Flushing

Flushing is a process of depriving your cannabis plant of water for a period of time before harvest. This allows the plant to use up any residual nutrients in the soil, which results in a cleaner, smoother smoke. However, flushing can also cause your plants to suffer from nutrient deficiencies if not done properly. Let’s take a look at the pros and cons of flushing your cannabis plants.


Flushing your cannabis plants is a process of watering them with pure water, without any nutrients, for a specific period of time. The purpose of flushing is to rid the plant of any residual nutrients in the soil, as well as to clean out the pipes and reservoir of your hydroponic system. Many growers flush their plants for the last two weeks before harvest, in order to ensure that the final product is as pure and clean as possible.

There are several benefits to flushing your cannabis plants:

1) Flushing helps to get rid of any residual nutrients in the soil, which can lead to a cleaner-tasting final product.

2) Flushing can help increase the potency of your cannabis by as much as 20%, due to the fact that it helps to get rid of any nutrient build-up in the plant.

3) Flushing helps to extend the shelf-life of your dried and cured buds, as it gets rid of any moisture that might be remaining in the plant material.

4) Flushing can help prevent problems with mold or mildew, as it removes any dead and dying leaves from the plant which could potentially harbor these unwanted fungi.


Flushing has some definite advantages, but it also has a few drawbacks. For one thing, it can be time-consuming, and it can be difficult to know when your plants are ready to be flushed. In addition, flushing may not remove all the unwanted chemicals from your plants, and it can also strip away some of the beneficial nutrients that your plants need.

How to Flush Your Cannabis Properly

There are a few things to keep in mind when flushing your cannabis. The first is that you need to give your plants enough time to flush. Depending on the size of your plants, you may need to give them anywhere from 2-4 weeks. Second, you need to make sure that you are flushing with pure water. This means that you should not use any additives or nutrients.

Flushing with Water

Cannabis plants are often flushed with pure water for the last 2-3 weeks of their life. This is done to help remove built up nutrients from the soil, so that the final product is less harsh and has a better taste.

To properly flush with water, you will need to gradually increase the amount of water you give your plants each week. Start by giving them twice the amount of water they usually get, and then increase this amount by 10-20% each week until you are giving them 4-5 times the amount of water they usually get. Be sure to check the soil frequently, as it can dry out quickly when you are watering more often.

You will know that your plant is properly flushed when the leaves start to turn yellow and fall off, and the buds start to swell. At this point, stop watering and allow the plant to dry out completely before harvest.

Flushing with Air

To flush with air, you need to stop giving your cannabis plants any nutrients, including water, about two weeks before harvest. Restricting nutrients will cause the plants to use up the ones already in their system, resulting in better-tasting buds. Letting your plants go completely dry will stress them, so make sure to flush with plenty of water a few days before cutting off nutrients entirely.

Once you’ve cut off nutrients, increase ventilation by opening windows or using fans to circulate air. The idea is to create as much airflow as possible without causing too much stress on the plants. You can also increase airflow by trimming away any excess leaves that are blocking air from reaching the buds.

After two weeks, your plants should be ready for harvest. Cut down the whole plant or individual branches, and hang them upside down in a cool, dark place to dry. Make sure there is good airflow around the drying area to prevent mold or mildew from forming on the buds.

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