DWC 18-Plant Storage Tote System

At a Glance

How This System Works

This system uses two 27-gallon dark storage totes placed side by side, each holding 9 plants in 3-inch net cups drilled into the lid. Together they create a compact 18-plant greens and herbs factory that can sit on a tabletop, shelf, or the floor of a grow room. Each tote acts as its own independent DWC reservoir with its own air stone, but both share a single dual-outlet air pump.

The 27-gallon capacity of each tote provides a generous nutrient reservoir that stays stable longer between top-offs and water changes. Because the totes are opaque, light is blocked from reaching the roots, which helps prevent algae growth. The wide, shallow shape of storage totes also means roots have plenty of room to spread horizontally, which leafy greens prefer.

This is a true set-it-and-check-it system. Once built, you fill the totes with nutrient solution, drop in your seedlings, turn on the air pump, and provide light. Leafy greens and herbs grow fast in DWC, so expect your first harvest of lettuce in as little as 30 days. By staggering your planting across the two totes, you can create a continuous harvest cycle with fresh greens available every week.

Materials List

Our philosophy: Use what you already have. Hydroponics does not require store-bought equipment. People around the world grow food this way using recycled containers, scraps of fabric, and seeds saved from last season's harvest. The links below are for convenience if you prefer to purchase, but we encourage you to improvise with what is available to you.

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Reservoir Totes

Two 27-gallon dark storage totes with lids. Opaque totes are essential to block light.

Use what you have: Any opaque plastic container will do. Old storage bins you already own, large coolers, or even repurposed utility tubs from a garage or laundry room. Just make sure light cannot get through to the water. If you need to buy new, a 10-gallon dark storage tote works great (you will need two).

Net Cups

Eighteen 3-inch net cups for leafy greens and herbs.

Use what you have: Small plastic cups with the bottoms cut off and holes poked in the sides work perfectly. Save yogurt cups, small deli containers, or anything similar. If you would rather buy them, a bag of 3-inch net cups (25-pack) covers this build with extras.

Aeration

A dual-outlet air pump with two air stones and tubing.

Use what you have: DWC does require an air pump for oxygenation. This is one component worth purchasing, but a basic aquarium pump from a thrift store or garage sale works fine. New pumps are affordable too: here is a solid aquarium air pump.

You can skip dedicated air stones and just poke small holes in bare airline tubing, though an air stone gives you finer, more even bubbles. This cylinder air stones (4-pack) gives you spares.

For tubing, reuse airline tubing from old aquarium gear, or grab standard tubing from any pet store. If starting from scratch, this airline tubing kit with check valves has you covered.

Growing Supplies

Starter plugs for seed germination and nutrients formulated for greens.

Use what you have: A scrap of sponge or a cotton ball tucked into the net cup will hold a seed until it sprouts. You can also transplant seedlings from a nursery. For convenience, Rapid Rooter plugs (50-pack) make germination foolproof.

Nutrients are one thing you genuinely need to buy. Plants growing in water need dissolved minerals. A single bottle lasts months. The General Hydroponics Flora Series (3-part kit) is the most popular choice.

Monitoring

Use what you have: pH test strips from a pet store or pool supply section are inexpensive and do the job. If you want more precise readings, a digital pH and TDS meter kit is a worthwhile upgrade.

Lighting (indoor growing)

A 4-ft LED grow light covers both totes placed side by side.

Use what you have: A sunny window provides enough light for many leafy greens. If growing indoors without natural light, basic 4000K LED shop lights from a hardware store work well. For a purpose-built option, these full-spectrum 4 ft LED grow lights are designed for plants.

You can turn lights on and off manually each day, but a timer is a huge time saver. Check thrift stores first, or pick up a programmable outlet timer.

Additional Materials (no affiliate link)

• Hydroton clay pebbles (one small bag). Perlite from old potting soil, small rinsed gravel, or crushed stone works fine as a substitute.
• Reflective tape or aluminum foil (optional, to wrap any translucent lids)

Tools

Use what you have: Trace a net cup on the lid and cut the circle with a box cutter or utility knife. A drill with a spade bit also works. For faster, cleaner cuts, a 3-inch hole saw is the right tool.

• Drill
• Measuring tape
• Marker
• Sandpaper (120 grit)

Build Instructions

Step 1: Mark the Lid Holes

On each tote lid, mark 9 evenly spaced holes in a 3x3 grid. Space them approximately 6 inches apart center-to-center, with at least 2 inches of clearance from the edges. Use a net cup to trace circles so you can verify spacing before cutting.

Step 2: Cut the Net Cup Holes

Using a 3-inch hole saw, drill all 9 holes in each lid. Sand the edges smooth so the net cup lips sit flush against the lid. Test-fit each net cup to make sure it drops in easily and the lip catches on the lid surface.

Step 3: Drill Airline Ports

Drill a 3/8-inch hole in the side of each tote, near the top edge, for the airline tubing to enter. Alternatively, you can route the tubing through the gap between the lid and tote body, but a dedicated hole keeps the lid sealed tighter.

Step 4: Install the Air System

Safety Warning: Always plug the air pump into a GFCI-protected outlet. Create a drip loop in the cord to prevent water from traveling to the outlet.

• Connect each outlet of the dual-outlet air pump to a length of airline tubing
• Attach an air stone to the end of each line
• Thread one line into each tote through the airline port
• Place the air stone flat on the bottom center of the tote
• Position the air pump above the water level or install a check valve on each line

Step 5: Fill and Mix Nutrients

Fill each tote with approximately 20 gallons of clean water (leave 3–4 inches of air space below the lid). Mix nutrients to an EC of 0.8–1.2 mS/cm for leafy greens. Adjust pH to 5.5–6.5.

Step 6: Plant the Net Cups

Fill each 3-inch net cup halfway with hydroton clay pebbles. Place a seedling in its starter plug in the center, then surround with more hydroton. The bottom of the net cup should just touch the water surface so the starter plug wicks moisture up to the roots.

Step 7: Assemble and Start

Snap both lids onto the totes with all 18 net cups in place. Turn on the air pump and verify vigorous bubbling in both totes. Position the grow light 8–12 inches above the tops of the net cups and set the timer for 16 hours on / 8 hours off.

Nutrient Guide

Crop Suggestions

Estimated Cost

Tips & Troubleshooting

General tips:

• Stagger plantings between the two totes by 2 weeks for continuous harvest
• Lettuce and herbs are light feeders; avoid pushing EC too high or you will get nutrient burn on leaf tips
• Keep a gallon of pre-mixed nutrient solution on hand for quick top-offs
• The totes are large and heavy when full; place them in their final position before filling

Maintenance Schedule

Daily

• Quick visual check: air pump running, bubbles visible, plants look green and healthy
• Check for any wilting or discoloration

Weekly

• Test pH and EC in each tote; adjust as needed
• Top off water levels (leafy greens drink less than fruiting plants, but evaporation adds up)
• Harvest mature outer leaves to encourage new growth

Every 2–3 Weeks

• Full water change in one tote (alternate totes each session)
• Clean air stones in vinegar if bubble output has decreased
• Remove any dead or yellowing lower leaves

Monthly

• Full water change in both totes
• Scrub interior walls of totes to remove any mineral deposits or biofilm
• Inspect airline tubing and replace if cracked or discolored
• Check air pump diaphragm and replace if output has weakened

Frequently Asked Questions

How long does the 18-plant tote system take to build?

Most people complete the build in two to three hours. Cutting the eighteen net cup holes across both lids is the most time-consuming step, so having a sharp 3-inch hole saw and a stable work surface will make the process much smoother.

Can I grow fruiting plants like tomatoes or peppers in this system?

This system is designed for leafy greens and herbs, which have smaller root systems and lower nutrient demands. Fruiting plants need more root space, stronger nutrients, and heavier support than the tote lid can provide. If you want to grow tomatoes or peppers, check out a dedicated 5-gallon bucket DWC plan instead.

How do I prevent algae from growing in the totes?

Use opaque, dark-colored totes and make sure the lids fit tightly with no gaps that let light through. If your lids are translucent, wrap them in aluminum foil or reflective tape. Algae needs light to grow, so blocking all light from reaching the nutrient solution is the most effective prevention.

How often should I change the nutrient solution?

A full water change every two to three weeks keeps the nutrient balance healthy and prevents salt buildup. Between changes, test pH and EC weekly and top off with plain pH-adjusted water or diluted nutrient solution as needed. With 27 gallons per tote, the large reservoir stays more stable between changes than smaller systems.