What is DWC Hydroponic System?

To the best of my knowledge, DWC hydroponic system is a very simple yet efficient method by which the roots of the plants are constantly submerged in a nutrient solution that is rich in oxygen. I am familiar with soil systems and DWC, and I have to say in all honesty that the difference in the rate of growth is just incredible—my lettuce just burst out when I first tried it! Unlike configurations like NFT or ebb and flow, DWC does not involve continuous delivery of nutrients. Instead, the roots are constantly submerged in contact with water, sometimes a blessing—and sometimes a curse if you do happen to forget about proper oxygenation. 

Key Components of a DWC Hydroponic System 

• Reservoir: A vessel in which the nutrition solution is held. I began with a 12-gallon tub at one point that was simply not large enough for my tomatoes, so I had to change to something bigger in the middle of growing. 
• Net Pots: Small baskets hold your plants and have their roots suspended in the water. 
• Optional Soil: My seedling soil is clay pebbles, but I occasionally forgot to drain it out and created some minor pH changes. 
• Air Pump: Provides oxygenated water. The air pump must be powerful; I used to have a very cheap air pump, and I lost my leaves because the roots did not get enough oxygen. 
• Air Stone: It aerates bubbles into microscopic bubbles. It’s more like a miniature jacuzzi for roots! 

How Does DWC Work?  

The net pots suspend the plants in mid-air near a reservoir of a nutrient solution. The air pump and air stone aerate the solution, so you don’t have to stress about the roots getting too much or too little oxygen—assuming you monitor the air pump (something I did for a whole day once, when my basil was nearly dead). 

Setting Up a DWC System: Step-by-Step Guide

1. Select a Reservoir: Use food-grade plastic buckets. It should be of sufficient size to accommodate the size of the plants you have. 
2. Drill Holes: When assembling your DWC hydroponic system, take precautions while drilling the holes for net pots so they can fit into the lid securely. 
3. Insert the Air System: Put the air stone at the bottom and fix the air pump. 
4. Fill with Nutrient Solution: Apply the suggested dosing of nutrients to your crop (which I had not done previously and scalded my lettuce leaves). 
5. Plant Seedlings: Plant them in net pots with or without media. 
6. Air Pump On: Keep it on 24/7 to deliver a good oxygen level. 

Water and Nutrient Management for Deep Water Culture  

To arrange water and nutrients in a proper way is indeed very crucial. Here are the key points. 

• pH Levels: At 5.5–6.5. I once left mine at 7.2, and they weren’t happy. 
• EC (Electric Conductivity): Measures the concentration level of your nutrient solution. 
• Water Changes: Change or renew the solution 1–2 weeks to prevent imbalance in the nutrients (I change mine on a weekly basis as a precaution). 

Aeration Needs of the DWC System 

• Use an air pump according to the reservoir size. 
• Use several air stones in the event your containers are wide and elongated. 
• Replace or clean air stones from time to time; if not used from time to time, they clog and reduce oxygenation significantly. 

Adequate Plant Selection for Deep Water Culture 

There are lots of plants for hydroponics. However, each plant may not be suitable for every system. Here are some crop suggestions for DWC: 

• Spinach, lettuce, and kale  
• Basil, mint, cilantro
• Tomatoes and strawberries  

Benefits of DWC

There are lots of benefits of this system; check these: 

• Higher Growth Rate: The largest advantage of any DWC hydroponic setup is the incredible growth rate, since there are nutrients available at all times. 
• Water Efficiency: The water is recirculated, so there is very little water loss (I had previously thought that hydroponics would mean constant refilling, but in reality, it is very efficient). 
• Less Moving Parts: No dirty timers and slick channels, which is nice for newbies. 
• Fewer Weeds and Fewer Pests: No soil means fewer pesky weeds and bugs, although I did have a snail on my net pot for the trip! 

Possible Disadvantages  

• Risks of Root Rot: One of the possible downsides of a DWC hydroponic system is not allowing enough oxygen levels, which will lead to possible root rot. 
• Nutrient Imbalances: Because the water is recirculated, you will have to be checking pH and EC so that your plants won’t be overfeed or underfeed. 
• Dependence on an Air Pump: No pump, no oxygen—your plants will starve faster than you can say “oh dear” if the pump breaks down. 

Problems and Fixes 

Every system encounters challenges, but every problem has a solution. Below are some common issues in hydroponic systems along with suggested fixes: 

Water Temperature Fluctuations

Problem: In DWC, warm water holds less oxygen and invites root rot. If your water climbs above 72°F (22°C), your roots might suffer.
Solution: Use a water chiller or freeze water bottles and float them in your reservoir. Keeping temps in the sweet spot (65–70°F) helps your roots breathe and stay healthy.

Low Dissolved Oxygen

Problem: In DWC, your plants depend entirely on oxygenated water. If your air stones or pump aren’t delivering, roots can suffocate.
Solution: Upgrade to high-output air pumps and use multiple air stones. More bubbles = happier roots.

Biofilm Buildup

Problem: Slippery, clear film in your reservoir or on tubing can harbor pathogens and clog lines.
Solution: Clean your system regularly with food-grade hydrogen peroxide or another safe sterilizer. A clean system is a healthy system.

Rapid pH Swings 

Problem: DWC systems with small reservoirs can experience sudden pH changes that stress plants and block nutrient uptake.
Solution: Monitor pH daily and use a larger reservoir when possible to stabilize your solution. Buffers (like silica) can also help.

Light Leaks into Reservoir

Problem: Even a small bit of light can promote algae and bacterial growth in DWC systems.
Solution: Make sure your reservoir and tubing are fully opaque. Use dark-colored lids and tape any seams or holes where light sneaks in.

Scaling Up Your DWC System

Scaling up? Simply add more pots or have a recirculating DWC (RDWC), in which many reservoirs lead into one master reservoir. This is easier to operate but harder to set up (I messed up the plumbing on my first attempt and had water everywhere in my garage). 

FAQs

How often do you top off the nutrient solution in a DWC system?

You must replace it every 1–2 weeks, although I also do a top-off halfway through if the water level drops more rapidly from evaporation or root uptake.

Can you use the DWC system to grow bigger plants like tomatoes or peppers?

Yes! Just be sure to give extra support to the heavier branches or fruits. I’ve used plain trellis netting with my tomatoes before, and it was lovely once I did get around to tying them up. 

Why are my roots turning brown in DWC?

Brown roots may indicate root rot, poor oxygen levels, or high water temps. Act quickly—clean the reservoir, lower the temp, and add beneficial microbes or oxygen boosters.

Can I run a DWC system without electricity?

Not for long. DWC relies on constant aeration. Without power, roots will become oxygen-starved quickly—usually within hours.