My DIY Hydroponic System: A Step-by-Step Guide
As the Head Farmer at Square Mile Farms, I’ve spent the last year experimenting with growing over 40 types of vegetables, herbs, and microgreens at our rooftop farm and office installations. With a passion for building and maintaining indoor hydroponic systems, I’m excited to share my knowledge and help you get started with growing your own food at home.
Getting Started with Hydroponics
Are you interested in hydroponics or growing from home but don’t know where to start? Do you want to make your own system by upcycling materials from your home? Growing hydroponically at home has numerous benefits, including a regular supply of fresh, nutritious produce that will save you from making frequent trips to the supermarket.
What is the Best Hydroponic System for Beginners?
Deep Water Culture (DWC) is the easiest type of hydroponic system to build and maintain at home. In this system, the plants grow with their roots submerged directly in nutrient-rich water. For home growers, this can be achieved by growing in large, opaque storage containers or buckets. Commercial growers use rafts that float on a large bed of water, allowing for continuous crops.
A Deep Water Culture System
The lack of moving parts or recirculating water makes DWC systems relatively simple and inexpensive to build. The water in DWC systems does not recirculate, it remains sitting in the reservoir for the entire duration of the plants’ lives. This means you must aerate the water to replenish oxygen that is used by the roots. In soil, air pore spaces provide the necessary oxygen for roots, and in recirculating hydroponic systems, water is aerated in the process of being pumped around.
What Can I Grow in My DWC System?
The best crops to grow in DWC systems are:
- Lettuce
- Kale
- Chard
- Bok Choy
- Basil
- Parsley
These are all plants that are not too top-heavy. In DWC systems, the roots are not well-anchored, and that means growing tall plants like tomatoes can be difficult, if you do grow them, you’ll need the right supports to keep the plant upright.
How to Make a DWC Hydroponic System at Home
Materials
You’ll need the following materials:
- Storage container or bucket
- Net pots
- Air pump with air stone
- Hard Water Liquid Nutrients (A & B)
- pH Down
- pH meter
- Measuring beaker
- Pipettes
- Hole saw with arbor
Method
1. Find a Suitable Container for the System
Many find that deeper storage containers and buckets work well for these systems because the deeper the reservoir of water, the more stable the nutrient solution will be. Fluctuations in nutrient concentration and pH are more likely in smaller reservoirs, and you will also have to top up the water more regularly. Light should not be able to penetrate your container, otherwise, there is a high risk that algae will grow in your water. I used a 55L opaque storage container, which we had leftover from a previous project.
2. Drill Holes into the Lid of the Container
The plants will grow in net pots, which are pots with plenty of holes for roots to grow through. The next step is to drill holes into the lid of the container where the net pots will sit. This requires the only specialist tool you’ll need in this build, a hole saw. The size of net pots you use must be larger than the hole so they don’t fall through.
If you’re using a wider container like mine, you can drill multiple holes. It’s essential to plan carefully here; I kept the holes 15cm apart to accommodate for the size of the mature plants. If you’re using a 20L bucket, I advise drilling one hole in the center to make a single plant system; they’re great for growing something larger like tomatoes or courgettes.
ProTip: Place some wood below your lid when you drill your holes; this will prevent the saw jolting and breaking the plastic.
3. Assemble Your Air Pump
The air pump must remain outside of the reservoir. It will come with a check valve, which ensures that the pump does not suck water back up if it is turned off. If it does not come with one, you must keep the pump above the water level.
Connect the air stone and check valve with a length of tubing, ensuring the arrow on the check valve faces the air stone. Then connect the check valve to the air pump in the same manner.
4. Fill the Reservoir, Add Nutrients, and Adjust the pH
The system can be quite heavy when full, so make sure you decide where your container will live before filling it up! Fill it almost full with water, leaving 1-2cm of space at the top. Next, you need to add your hydroponic nutrients to the water, following the instructions on your bottle. Mine advised me to add 2ml per liter of each A and B nutrients using a measuring cup. I added 110ml of each into my 55L container.
We also need to adjust the pH of the water. Using a pH meter, measure the pH; tap water will be anywhere from 6.5-7.5 pH. Most vegetables and herbs require a slightly acidic nutrient solution. You can bring the pH down to 5.5-6.5 with drops of phosphoric acid using a pipette commercially sold as pH Down for hydroponic use. Wear gloves when handling pH down and remember to mix the solution well after application.
5. Assemble the System
Plug in the air pump and place the air stone in the reservoir. Secure the lid on top, and you’re almost finished.
Adding your plants is simple; I placed some plants grown in rockwool plugs into the net pots. You can use seedlings grown in soil too, but we advise using a medium that doesn’t make a mess. Rockwool plugs or hydroton clay pellets are a cleaner solution.
How to Maintain Your Hydroponic System?
Now that you’ve built your DWC hydroponic system, it’s essential to maintain it correctly. Here are some must-dos:
* Keep an Eye on the pH Levels: Check the pH levels every time you top up the water.
* Monitor the Water Level: Ensure the water level doesn’t drop too much, especially when the plants are young. As long as the water has sufficient contact with the roots, they should grow well.
* Top Up Water and Nutrients: Use an old 2L water bottle to top up your water so you know exactly how much water you are adding. For every 2L of water I use, I add 4ml of each A & B nutrient into the reservoir.
* Clean and Replace the Reservoir: Clean the reservoir and replace it with fresh water every 14-21 days.
Additional Tips
How to Sow Seeds Directly into Your DWC System:
If you don’t have a way of propagating young seedlings, you can directly sow seeds so they germinate in the system. To do this, place a rockwool plug into a net pot and place a seed or two into the plug. Ensure that the plug does not dry up at all, or this could affect germination.
How to Grow Cuttings in Your DWC System:
You can also experiment with growing herb cuttings. I tried it with a mint cutting using a foam collar, which is a sponge cylinder with a slit down the middle that you can wedge seedlings or cuttings into. I cut a mint stem under a leaf node, and then removed the bottom leaves and placed it into the foam collar and then net pot. Placing a bottomless plastic bottle over the cutting is advised to prevent it drying up.
Final Thoughts
So that’s how you can build a simple hydroponic system for yourself at home. You may already have some of the materials in your home right now; an old storage container or bucket can be repurposed in a worthy effort to start growing from home. If you don’t have a lid, you can cut holes out of a sheet of polystyrene packaging for plants to grow from.
When you’re first getting into hydroponics, the complexity of some of the systems on the market can be overwhelming. That’s why we recommend starting simple; a DWC system gives beginners an opportunity to do this. They are low maintenance and can be placed anywhere that has sufficient light, indoors or outdoors. If you’d like to make a simple hydroponic system, then give this method a try.
Share Your Efforts: Share your efforts with us on Instagram or send us pictures of your new system to [hello@squaremilefarms.com](mailto:hello@squaremilefarms.com). And don’t forget, we’re here to help! Get in touch if you need some tips/advice on setting up your hydroponic system.
About Square Mile Farms:
Square Mile Farms bring vertical, urban farming to city dwellers in their homes and in the workplace. We aim to bring people closer to food production and help create a culture of healthy, sustainable living. Find out more about our offering for homes and offices and get in touch here with any queries. Sign up to our newsletter for tips on a healthy lifestyle and a roundup of relevant news. You can also follow us on social media to stay up to date with our journey, find us on Instagram, Twitter, and Facebook. Why not join our online Urban Growing Community for advice on growing at home and much more!
Materials Product Suggestions:
* Storage container or bucket
* Net pots
* Air pump with air stone
* Hard Water Liquid Nutrients (A & B)
* pH Down
* pH meter
* Measuring beaker
* Pipettes
* Hole saw with arbor
What is a Deep Water Culture (DWC) system? It is a method of hydroponics where plants grow with their roots submerged directly in nutrient-rich water.
What are the benefits of a DWC system for beginners? It is simple to build, inexpensive, and low maintenance, making it ideal for beginners.
What types of plants can be grown in a DWC system? Lettuce, Kale, Chard, Bok Choy, Basil, and Parsley are good choices due to their suitability for DWC.
What materials are needed to make a DWC hydroponic system? Storage container or bucket, net pots, air pump with air stone, hard water liquid nutrients (A & B), pH down, pH meter, measuring beaker, pipettes, and a hole saw with arbor.
How do you prepare the reservoir for the DWC system? Fill the reservoir with water, add nutrients following instructions, measure pH, and adjust it to 5.5-6.5 using pH down.
What steps are involved in assembling the DWC hydroponic system? Drill holes in the lid for net pots, assemble the air pump, fill the reservoir, add nutrients and adjust pH, add plants, place the air stone in the water, secure the lid, and plug in the air pump.
How do you maintain a DWC hydroponic system? Monitor pH levels, maintain water level, top up water and nutrients regularly, and clean and replace the reservoir every 14-21 days.
Can you sow seeds directly into the DWC system? Yes, you can by placing a seed into a rockwool plug inside a net pot, ensuring the plug stays moist.
How can you grow cuttings in a DWC system? Place a cutting (e.g., mint) in a foam collar inside a net pot, cover with a bottomless plastic bottle to prevent drying.
What advice is given for troubleshooting or sharing your progress? Share your progress on Instagram or send pictures to hello@squaremilefarms.com; they offer tips and advice.
