DIY Hydroponics – Build a Homemade Indoor Marijuana Grow System

A hydroponics grow system is the most efficient way to grow marijuana indoors and if you’re on a budget, taking the DIY approach will prove to be very cost-effective. Homemade hydroponic systems for growing marijuana indoors can be just as effective as ones you purchase, but putting the system together and making sure it’s built right can be a major downside.

With our step-by-step guide you can build your own homemade hydroponics grow system for cannabis within just a few hours.

Step 1 – Purchase the Materials

Water culture is the most popular type of hydroponics system and it’s the type we commonly sell here on the website. Water culture hydroponics is easy to maintain, easy to build and it’s low cost. Essentially, your plant’s roots will be suspended in nutrient enhanced water that’s contained below the plants. Water culture provides a great return on investment, accommodating for as many as 4-6 plants per 5 gallon container. Here are the common materials for a water culture hydroponics system:

  • Air pump – Used to provide oxygen to the roots of the plants by creating air bubbles within the nutrient solution.
  • Air stone – Placed at the bottom of the water container. The air pump tubing should connect to the air stone.
  • Tubing / Air line – Will most likely be sold with the air pump. Connects the pump to the air stone.
  • Waterproof container – Could be a plastic bucket, bin, fish tank or some other water reservoir.
  • Styrofoam or some other material to suspend the plants above the water, then use net pots to secure the plants within the Styrofoam. (Some bins/containers may have lids and therefore you won’t need Styrofoam. You can drill holes in the top of the lid for the plants, then place net pots into the holes.)
  • Net pots – Used to place the grow medium and plants in.
  • Grow medium – Used to grow the plants in, since there is no soil.
  • Hydroponics nutrients – Macro and micro nutrients to place into the water to supply the nutrients to the plants.
  • pH testing kit – To test the pH value of the water and make sure it’s within the right range.
  • TDS/PPM meters – Tests the water for “total dissolved solids” and analyzes electric current to test the strength of your added nutrients.
  • Temperature meter – Tests the water temperature and room temperature to ensure you’re growing in proper conditions.
  • Grow lights – This is only essential to begin growing and is not needed to build the hydroponics system.

Step 2 – Decide on the Container / Water Reservoir

The container that you decide on will be used as a water reservoir to hold the nutrient water that feeds your plants.

Fish tanks work well but will need to be painted black to retain light within the system and keep any outside light from getting in. Allowing light into the water reservoir could promote the growth of algae.

Plastic bins and containers are ideal options as they are almost always sold with lids that you can drill holes into, to avoid having to use Styrofoam to suspend your plants above the water.

Step 3 – Prepare the Water Reservoir for Use

If you’ve used a fish tank or something without a built in lid, you will need to cut Styrofoam to the correct length and width to rest comfortably at the top of the water. For instance, if your water reservoir measures 35″ in length by 24″ in width, you should cut the Styrofoam to 34 3/4″ x 23 3/4″. This will provide adequate space for the Styrofoam to adjust as the water level changes.

Now you can cut holes in the Styrofoam for your net pots. Trace the bottom of the net pots onto the Styrofoam and use that as an indicator on where to cut.

If your water reservoir has a built in lid, you should cut holes in the top of the lid using the same procedure. Make sure the holes are small enough that the net pots won’t slide through. You do this by tracing the bottom of the net pots onto the lid.

The number of holes you should cut is dependent on the number of plants you intend to grow. A 5 gallon container can generally provide enough space for 4-6 plants.

Step 4 – Prepare the Air Pump

Now you can setup your air pump.

Connect the air line to the pump. Cut a small hole in the lid/Styrofoam of your water reservoir so that the air line can be fed into the container.

Now feed the end of the line that’s opposite from the pump into the container. Place the air stone at the bottom of the container (in the middle) and connect the end of the air line to the air stone.

This means the air line must be long enough to reach the bottom of your water reservoir.

Step 5 – Fill with Water and Add Nutrients

Once you have the pump and water reservoir prepared, you can begin to fill it with water.

After the water has reached the top of the reservoir and will reach the plant’s roots, shut off the water and add the nutrient solution.

Be sure to follow the directions and only use as much nutrient solution as recommended. Adding more nutrients will kill the plants.

Step 6 – Add Grow Medium to the Net Pots and Insert Plants

You’re almost there!

Now you can add your grow medium to the net pots and insert your plants into the grow medium. Make sure the roots of the plants are suspended below the net pots and into the water.

The system is ready and you may plug in in the pump to start using your homemade, DIY hydroponics system!

Don’t forget to setup your grow lights above the plants. – Marijuana plants need light, carbon dioxide and water to survive.