Hydroponics In A Ball Jar – How To Make It

Growing plants with hydroponics is easier than you may think. Yes, it requires specialized water-soluble nutrients, but with just a few supplies you can get started with a simple system, quick.

In this article, we’ll show you how to make a DIY glass Ball jar hydroponics setup! It is easy, fun and looks pretty cool when it’s done.

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Ready to use hydroponics Ball jar.

Video Setup:


Supplies:

To make your own hydroponics Ball jar, you’ll need a few basic supplies. Here are the very basics needed to make your own system.

  • Ball Jar, Lid and Seal. You can get mason jars online at Amazon or for much cheaper at most local hardware stores. They are also available at major department stores. We are using 1 quart sized jars, but you can go smaller or larger depending on how large of a grow space you have.
  • Net Pots. Net pots are used to suspend your plants above the water in the container. They are available for cheap online, or you can sometimes find them at nurseries. There are 2″ net pots and 3″ net pots. The 3″ pots will fit perfectly inside of a wide mouth ball jar, but they are bigger than needed for most plants. We are using 2″, but 3″ will certainly make the job easier!
  • Spare Plastic (optional). If you are using 2″ net pots, you’ll need some spare thin plastic to create a ring. This is where the net pot will hang and will close securely beneath the jar lid rings. This can come from an empty food container or similar.

    Tip: If you have one, use a black Tupperware container – this will block out light and won’t need to be painted.
  • Paint or Opaque Paper. We must cover the Ball jar to avoid algae growth in the water reservoir. Black spray paint is ideal for blocking the most light. We used a layer of black, followed by a layer of golden yellow for aesthetics. We used this spray paint.
  • Rock Wool & Hydroton. These are only needed when you are ready to start growing plants in your Ball jar. Rock wool is a favorite medium used for sprouting seeds. Although it is natural, be careful when handling rock wool as it can be a skin and lung irritant. Hydroton is simply dehydrated clay stones. Be sure to wash and dry them thoroughly before using.
  • Pump, Hose & Air Stone (optional). Since we primarily grow peppers, we chose to set up a water culture method, which involves pumping air bubbles at the bottom of the water. The bubbles pop at the water’s surface, creating a humid environment for the root systems to stay moist and collect oxygen. The alternate method is called Kratky, which we will cover later.
Ball Jar Hydroponic Lid Setup
Basic supplies for Ball jar hydroponics.

How To Make a Hydroponics Ball Jar

With all the required supplies on hand, you are ready to assemble your hydroponics Ball jar! If you are painting the jar, the process may take a day or two to allow it to fully dry. Otherwise, you should be able to get your jar set up within an hour or so.

Steps:

  1. Paint the jar.

    If you are painting your jar, start by taping the rim where the lid screws on. This part doesn’t need to be painted. Bring the jars outdoors and place them on cardboard or paper bags, upside down. Apply as many coats as desired and allow to dry thoroughly.

    If you are not planning to paint the jar, you’ll need to cover the jars with something opaque, such as brown paper. Get creative! As long as light cannot penetrate into the jars, you are good. Some people use rubber bands or tape to keep the covering in place.

  2. Cut the plastic ring.

    If you are using 3″ net pots, they should fit perfectly into wide mouth Ball jars. If you have 2″ net pots, trace 2 circles onto your flat piece of plastic. For the larger circle, use the Ball jar lid seal. Then, use the rim of the net pot to trace a second circle inside of it, right in the center.

    Cut out the center circle first, erring on the side of too small rather than too large. If the circle is too big, the net pot will simply fall through. Test the net pot to ensure it fits well, then cut the outer circle out. When finished, the ring should fit snugly beneath your Ball jar lid rings atop the jars.Ball Jar Lid Painted

  3. Punch a hole in the ring.

    If you are using an air pump, you’ll need a place for the tubing to run into the jars. Most standard tubing is 1/4 inch, meaning a standard hole punch will do the trick. Punch a hole in the plastic ring, ensuring it is accessible while the lids are screwed in place.

  4. Set up the pump and air stone.

    If you are using the deep water culture (DWC) method, cut the tubing to length, ensuring the back valve is in place between the pump and your jar. Connect the air stone and place it at the bottom of the jar, feeding the tubing through the punched hole.Ball Jar Hydroponics Air Pump Tubing

  5. Assemble the jars.

    Once the paint is dried and your net pots are secured in place, your hydroponics Ball jar is complete! All that is left is to set germinate seeds and provide nutrient-rich water under some grow lights.Ball Jar with Net Pot


DWC vs Kratky Method

If you are on the fence about which hydroponic method to use, consider the benefits and drawbacks of each. Here are the basics.

DWC Method (Deep Water Culture)

The water culture method involves pumping air into your nutrient solution via an air stone. The air stone is a porous piece of rock that creates tiny bubbles when air passes through it.

The air bubbles serve two purposes. One is to provide the roots with oxygen. The other is to keep the roots moist while they grow. Roots that are not submerged in water can dry out without the constantly popping bubbles from the air pump.

Hydroponics Air Stone
Air stone produces tiny bubbles when connected to an air pump.

Your pump will probably run 24/7 if you are using DWC, and generally involves more setup. However, it has been shown to grow more robust plants, especially fruiting plant varieties, such as peppers and tomatoes.

If you are just growing leafy greens or herbs, Kratky should be just fine.

Benefits:

  • Faster plant growth
  • Healthier root systems

Drawbacks:

  • More setup and supplies needed
  • More maintenance
  • May lead to more algae growth

Kratky Method

The Kratky method of hydroponics is a much simpler setup. The idea is to leave enough room between your plant’s roots and the water line for the roots to gather necessary oxygen. As the plants grow, the water level drops and the roots have more room to breathe.

If you plan to grow lettuce, spinach, basil or anything else that is purely leafy, Kratky should work well. If you intend to grow peppers or tomatoes, DWC is recommended.

Benefits:

  • Easy setup
  • No electricity for air pump

Drawbacks:

  • Slower plant growth (usually)

Either method is proven to grow healthy plants, but choose your method carefully based on what you intend to grow hydroponically.


Other Things To Consider

This article is focused on creating a setup to grow plants in. For more info on actually getting started with planting, use these resources.

Lighting – Learn more about choosing a grow light here.

Nutrients – We use General Hydroponics granular nutrients and follow the directions for feeding.

Growing Peppers – We specialize in growing peppers. If you want to try your hand at growing some peppers, see our grow guide here.


I hope you enjoy this project as much as I did. Follow our YouTube channel to see our hands-on videos, especially if you love peppers!

Calvin Thumbnail

Calvin

One of the original Pepper Geeks! When Calvin isn’t gardening or learning more about peppers and botany, he might be traveling new places or playing some music.

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