How to make a small, passive hydroponic pot

Passive hydroponics is quite easy to setup and requires no electricity so you can use it anywhere. I’ve tried many different designs for passive hydro and wick based designs before coming up with this beauty. These bottles rely on the medias wicking ability until the plant has grown it’s roots down into the mini-reservoir. After that they feed just like DWC except you need to manually keep the pot topped up with nutrient solution. (But hey, who doesn’t like watering their plants?) Today I’m going to teach you how to make one.

You will need:

- a small plastic picnic cup

- a small empty water bottle, about 350ml

These should fit together reasonably well assuming the water bottle is pretty straight.

- perlite or another inert medium

- a plant (I don’t use these containers to start seeds but they’re great for seedlings)

- (optionally) some spray paint

Step 1: Cut the top of the bottle off using tough scissors. Be careful! It’s easy to get cuts trying to cut through plastic. Try putting the picnic cup inside the headless bottle. Trim the bottle’s height so that there are at least 2cm of space at the bottom. If the cup and bottle fit together well enough move on to step 2.

Step 2: Using scissors or a drill with wood bit cut some holes into the bottom of the picnic cup. You need the holes for nutrient uptake at first and later for the roots to grow through. You are making a diy net pot.

Step 3: (optional step) Spray paint the water bottle a nice dark color to discourage algae growth. I masked out a strip on the side so that I can see where to fill to.

Step 4: Pot up the plant you chose using the picnic cup and the media of your choice. I picked perlite.

Step 5: Fill the mini reservoir bottle so that when you put the picnic cup inside, nutrient will feed the media for wicking.

All done! Now just wait until the roots get long like my spearmint. Mmmm spearmint