DIY Deep Water Culture Herb Garden

As promised, I documented each step in the process so, should you wish, you can build your very own hydroponic system. Here are the materials that you will need for this project:

• storage bin with a flat lid
• black spray paint
• net pots
• grow medium (hydroton)
• air pump
• air tubing
• air stone
• seedlings in rock wool or other hydroponic starter material
• nutrients
• pH test kit

Once you have all of your items, here's how I went about assembling the kit.

This is the storage bin I chose. Two factors made me grab this one; a flat lid and a good depth. The deeper the container, the more room your roots will have to grow and the longer your nutrient bath will last.

I traced around the pots where I planned to cut the holes in the lid.

All eight pots were traced. This is not the size of the holes to cut though, I free-handed smaller circles inside these that were about 1/4" from the edges so the pots would not fall through the lid.

I used a Dremel with a spiral cutting bit to cut out the smaller circles.

Finished cutting, now to spray paint.

I placed a strip of masking tape at one corner. This is to leave a 'window' to see the water level without opening the lid.

Painted and waiting to dry. I used Rustoleum flat black paint. It is crucial to paint the container black (or another solid color) so as not to allow sunlight to penetrate to the water and to prohibit the growth of algae. You do not want algae growing in your nutrient bath. If you discover any, wash out the container and refill with fresh nutrient bath solution.

After paint dried and with the lid placed on top. The masking tape was removed as well for the 'window'.

The air stone ($3), airline tubing ($3), and air pump ($7) were all purchased from wally-world. I hate going there, but it was better than a trip to the next town solely for these three items at the hydroponic store.

I picked these 4" pots up from the local garden store. They were used, so they let me have them for $0.05 each. My plan was to drill holes in them and make my own net pots. After breaking one or two using a drill and bit (thank goodness I bought extra), I found that the Dremel with the spiral cut bit worked the best. Each pot averaged about 60 holes each and for 8 pots that means I drilled approximately 480 holes! It took me a good solid hour sitting at the workbench drilling the holes. If I were to do this again, I would just buy the net pots for the $.50 they cost. However, in this case, that would have meant driving 20+ miles to the next town to get them, so maybe it was worth it? 

Everything ready to begin assembly.

A 3/8" hole was drilled a close to the top of the container as possible to pass the air line through. Be sure to check for clearance with the lid and be mindful of your waterline level. It may be best (depending on your container) to run the air line through the top of the lid.

Air line ran and air stone placed.

Lid on.

Home-made (and homely looking) net pots placed.

Pots filled with hydroton. I have run across others that have used pea gravel as their medium and claim it works, but I would recommend using the appropriate material if you can. Either way, you need to wash the medium before using it. To wash hydroton I have a 5 gal bucket with small holes drilled in the bottom that I pour them into and rinse with a water hose. A full bucket takes several 'baths' to come clean. The next time I wash some I'll take photos of my process and post it.

The hydroponic herb garden sitting in it's home! It's placed next to a southernly-facing window in  our home atop a stool.

And another view, showing the placement of the air pump. I zip-tied it to the stool.

When your air pump is below the waterline of your container, it is very important to install a one-way check-valve to prevent water back-flowing into your pump and causing failure. To my surprise, this $7 pump came with one! I can't say that about my larger pump!

Reservoir filled with water and air pump on... we have bubbles! Now is the time to inspect your air stone and make sure it is producing adequate bubbles and is working properly. Oxygenated water is vital to hydroponics.

I filled my container one gallon at a time. After each gallon, I used a marker to indicate in the 'window' where each gallon's level was. From this, I learned that my reservoir takes 6.5 gallons to fill. You MUST know how much water is in your system to measure the nutrients appropriately.

Lid on and air pump going. The air pump runs continuously. Also notice that you can see the water line in the 'window'. You want to allow the water to sit for a day or two prior to introducing plants to it. This time will allow the fluoride and other water treatment chemicals to evaporate.

You want your 'Full' water line to be about 3/4" above the bottom of your pots. In this photo the bottom of the pot is the shadow. As your plants grow and their roots lengthen they will grow down into the nutrient bath, so keeping the container full is not as vital as when the seedlings first get placed. Either way, it is best to keep your container full.

And there you have it! All-in-all I believe the items cost me under $25, $50 if seedling trays, starters, medium, etc. are needed. Even at $50, having fresh herbs available that YOU grew is worth so much more! Especially with the amount of toxic chemicals used in the commercial food market today. Now we're waiting for the seeds to sprout to place into the kit. We're hoping they'll be ready in 3 days.

More to come...
-Sam