Tips for Watering Your Cannabis Plants

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For the perfect growth of your cannabis plants, you must know how to water them without making mistakes. Proper watering depends on the stage of cultivation. Here’s a guide discussing four watering tips to grow your cannabis plants ideally!

A quick preview – this guide discusses the best water for cannabis, when/how to water them correctly, and other crucial details.

Let’s dive in!

How to Water Cannabis Plants: 4 Expert Tips

  1. Select the Right Soil Medium

Rich, airy, and fluffy soils are well-draining and ideal for cannabis. A great example of such soil is CocoCoir which retains water. If you mix CocoCoir with Perlite, it becomes a great medium to plant your cannabis. Adding Perlite to the soil enhances the structure by creating air pockets. No matter how wet the medium is, Perlite creates air pockets in the soil and helps with drainage.


Woman's hands transplanting soil into a new pot to grow cannabis in
Cannabis grower at an indoor farm transplanting cannabis plant into new dirt pots
  1. Switch to The Right Container as Needed

Selecting the right container size to grow cannabis plants is fundamental. Larger containers give the plant the required water and nutrients as it grows. Remember – as the cannabis plant grows, you must change its container at every stage.


  1. Ensure Proper Drainage

Your plant must have a proper drainage system to obtain nutrients and water. But, keep water runoff to a minimum when watering plants, ideally around 20%.

You can easily create a drainage system using a container with holes in the bottom. Buy pots like that or make the holes in containers yourself. Use a saucer or some kind of catcher for the runoff water to prevent drowning the cannabis plants. This also reduces the chance of growing mold or root rot.

Hands holding wet soil with young plant growing
A hose watering three buckets with cannabis plants in them
  1. Avoid Over or Under Watering

Determining how often to water cannabis plants depends on various factors such as humidity, temperature, and container size. However, there’s an easy way to discover whether your cannabis needs watering. You can use a moisture meter or simply check the soil’s moisture level by inserting your finger into the soil up to the second knuckle.

In general, with proper drainage, cannabis plants require watering once every two to three days during the vegetative stage and more frequently during the flowering stage.

The Best Water for Cannabis


Before choosing any random water source for your cannabis plant, test its mineral, pH, and temperature attributes. For healthy cannabis growth, the water must contain certain minerals and pH levels.

When growing hydroponically, a pH of 5.5-6.5 is recommended. On the other hand, a pH of 6 – 6.8 is recommended for soil-grown plants. If you maintain the ideal water pH balance, your plants absorb more nutrients through their roots since different nutrients are absorbed by the roots at different pH levels.

Plants require minerals to grow large and healthy. And the water you use to produce them serves as the main source of nutrients for their root absorption. After cloning, keep the mineral content in the water between 500 to 600 ppm. When vegging, this should be between 800 to 900 ppm.

Finally, for the flowering stage, make it 1000 to 1100 ppm. The water temperature must be optimal, too, between 68 to 73 degrees F.

How to Avoid Nutrient Burn?


When marijuana roots intake excessive nutrients, they can experience nutrient burn. This can occur during any stage of their growth, killing the plant entirely. So, avoid overwatering, over-mixing nutrients, or adding excessive nutrients to your plant as they cause a nutrient burn.

Use UV Light Filters to Water Cannabis


UV light filters are not used to water cannabis. Still, you can use UV light to treat the water used for irrigating cannabis plants to eliminate harmful pathogens, improve plant health, and avoid chemical residues.

At Aqua Ultraviolet, we offer UV light filters – a versatile technology to disinfect water. Our UV filters use the same germicidal rays as the sun but are hundreds of times more powerful. It’s a cost-effective, environmental-friendly way to get clean water for growing plants.

Our UV filters provide a purely physical process that includes no chemicals. Our solution disinfects water without altering water’s chemistry, taste, smell, or pH levels, giving you the perfect water to grow cannabis.

So, order Aqua Ultraviolet’s UV filters today and enjoy worry-free installation and warranty with direct technical support from our team!

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For over three decades, Aqua Ultraviolet has been the premier manufacturer of ultraviolet sterilizers and bio-mechanical filtration.

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