How to Use Water for a Hydroponic Grow System

The beauty of growing an indoor hydroponic grow system is that it gives you full control of the water supply as well as quality and most importantly the combination of nutrients in the water. Being able to control these factors means you can create the perfect conditions for your marijuana plants to prosper.

While a hydroponic might seem a lot more complex than growing outdoors or using soil at the first glance it will only take you some time to learn and study but it will be far less work when set up.

Your plants basically live off light, water and nutrients. We have discussed grow lights before, so today we will be looking into the science of water management to improve your yield.

When setting up your water system these are the parts that will be important for you:

  • watering your plants vs growing within water (also know as hydroponics)

  • nutrients (which we will cover in our nutrient article!)  

Let’s get started!

What is Deep Water Culture?

This popular way to grow hydroponics means that your plants grow in a well-oxygenated solution of water and nutrients instead of growing medium. The method is called deep water culture (short: DWC) because your plant’s roots will be submerged in water all the time.

An air pump will infuse the water with air so that the plants will not drown. You will add all the nutrients that your plants need to the water.

Think about it: The fact that you are growing within water means that you never have to think about watering your plants again. Yeah.

Fact is that this system is one of the easiest way to get started with growing marijuana professionally. There are some things to consider when setting up your DWC system but once you invested this initial time and money there will be very low maintenance for you.

Bonus: Your plants will grow extra fast in comparison to growing in soil!

On that note: This system works best for larger amounts of plants. In small systems the quality of water and levels of nutrients might vary too much which will cause extra work for you and distress for your plants. Set up a hydroponic grow system if you are aiming for a commercial production.

Pro Tip 1

Make sure you have a back up in place in case of an electricity outage. Without the air pumps your plants might drown in the low-oxygen water.

How to Set Up a Recirculating DWC system

To set up your production you are going to need:

  • several buckets of 5 gallons

  • an air pump

  • air stones

  • airline tubing

  • water tubing

  • net pots

  • growing medium

  • hydroponic nutrients

Pro Tip 2

Get a pH control as well as a PPM meter. PPM means parts per million and describes the concentration of minerals and nutrients in your water. The pH level will affect how well your plants are able to absorb the nutrient solution. You might have to use phosphoric acid to lower the pH of your city water. A pH between 5.5 and 7 is fine without need for adjustment.

What you want to do is: Get your plants into the growing medium and place them into the net pots. The net pots go above the buckets. Within in the bucket of water you will find the air stone which adds oxygen through infusing bubbles into the water. The water running from bucket to bucket will be shuttled around adding extra oxygen. The air stone is connected to the air pump via airline tubing. All your buckets will be connected to a recirculating system.

Plants growing in the deep water culture will grow a lot faster than plants in regular soil. Because water and nutrients are always available to them they can put all their energy into growth and budding. Who would not like to be harvesting weed more often?

Because your buckets will all be chained together it will allow you to manage water, oxygen and nutrient for all of them at once. Be aware of sudden changes in pH, PPM and water temperature because this may damage your plants. Monitor these at all times. This is next level marijuana growing and will set you apart from the hobby growers.

Pro Tip 3

Pay attention the the temperature of the water you are using. You do not want to go higher than 68 degrees because than the oxygen level will start to fall. Think about using a water chiller if you are living in a very hot area. If you go lower than 60 degrees however your plants might think they are going into fall or winter which will stop them from flowering. You can use aquarium heater to heat the water.

For successfully growing in a DWC system you are going to want to make sure that only the root matter is submerged into the water. No stem and no vegetation. Keep about 1.5’’ of roots above the water line.

Pro Tip 4

Make sure to monitor your plants for root-related diseases. Remove and destroy sick plants immediately. I am serious about this. Remove IMMEDIATELY.

Go Professional with Hydroponics

Going hydroponic and setting up the right system for water and nutrients is what differentiates the novice from the master. A hydroponic grow system could be the key to your best yield ever.

Keep in mind that you want to create the best environment ever for your plants. At the same time you want to automate your grow processes as much as possible. This will decrease your working time whilst increasing the quality of your output. Setting up a light system on timer is the first step. Creating a hydroponic production like DWC will allow you to manage water and nutrients at one single place. No matter how big you grow.

So consider this approach when taking your cannabis production to the next level.

Make sure to check our article on nutrients to understand how to improve your water quality with the right levels of nutrients. Managing your nutrients is essential for your plant’s health and your amount of yield. Quality of water is your best advantage.



  • what would happen if you had carbonated water.?

  • I bought a hydroponics kit but can’t get seeds to grow I’m sprouting them then place them in cushion with water and lights but they never grow please let me know know what I’m doing wrong

  • Great article – lots of people neglect the importance of water, and in a hydro system, that could cost you your grow. Thanks for posting!

  • Great advise.Thank you.Is there information available from a Pro grower on the results of growing commercial using Aeroponics 100% in large scale growing?

    William Sharpe

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