My Journey with Hydroponics

[Bill Ryan]

Szymon, I have a very general question. (And thanks for all the interesting detail you've posted on this thread!)

Can you say a little about simpler ways to do this? Maybe for someone who doesn't have a workshop and may not be as practically minded or skilled as yourself?

What you're creating is inspiring, but (maybe to some) also a little daunting, just because of the complexity and all the handiwork needed.

I can see that there are easy-to-assemble kits that anyone can order online. Like these:

https://nthydroponics.com/collections/hydroponic-kits

Is your impressive DIY system

• More efficient?
• Cheaper?
• Better adapted to your own needs?
• Simply more fun to build?
  
  

[Szymon]

Posted by Bill Ryan (here)
Szymon, I have a very general question. (And thanks for all the interesting detail you've posted on this thread!)

Can you say a little about simpler ways to do this? Maybe for someone who doesn't have a workshop and may not be as practically minded or skilled as yourself?

What you're creating is inspiring, but (maybe to some) also a little daunting, just because of the complexity and all the handiwork needed.

I can see that there are easy-to-assemble kits that anyone can order online. Like these:

https://nthydroponics.com/collections/hydroponic-kits

Is your impressive DIY system

• More efficient?
• Cheaper?
• Better adapted to your own needs?
• Simply more fun to build?
  
  

Hey Bill,

You're right. I like to over-engineer my projects, so they last several lifetimes. I did the same for the house. I think the easiest method for everyone else is the Kratky method. Get an aquarium air pump for oxygen. Put that in a black, food-safe container. Make 9 holes in the lid. Get a few net cups, or just use a flat piece of foam, cut it into a circle, make a notch in the centre, and fill it with your solution. The roots need to touch the solution. Don't submerge the entire root system, or the plants will drown. No oxygen.

You will still need to get your seedlings started. There are many ways to do this. When your seedlings have developed a root system long enough to touch the solution (about 2 cm), place the seedling into your net cup, fill it with your grow media (I use clay balls), or place it into the notch of your foam and transfer it to the black, food-safe container. Switch on the pump to provide oxygen to the solution, and you should be good to go.

Make sure the water level is right, and the solution is topped up. Make sure your EC and pH levels are spot on for what you are trying to grow.

I will also use the Kratky method to grow, but my focus right now is to get the RDWC method going first.

I suggest waiting until I'm finished with setting up, as I will then show the forum how to set up for the Kratky method. There is not much to it.

Stay tuned. Cheers. Szymon

[Szymon]

Here is a breakdown between the two methods.

The Kratky method and RDWC are both hydroponic growing techniques, but they operate very differently in terms of complexity, cost, and plant performance.

Core difference (simple view)
Kratky = passive, no electricity, “set and forget”
RDWC = active system, uses pumps, high performance
How each system works
Kratky method
Plants sit in a container with nutrient solution.
No pumps, no circulation, no aeration.
As water level drops, roots get exposed to air → natural oxygen supply.
You don’t refill (ideally) during the grow cycle.

Key traits:

Extremely simple
No moving parts
Cheap to set up
Minimal maintenance
RDWC (Recirculating Deep Water Culture)
Multiple buckets or sites connected to a central reservoir.
Water is constantly circulated with a pump.
Air stones supply oxygen to roots continuously.
Nutrients, pH, and temperature are actively managed.

Key traits:

Highly oxygenated root zone
Constant nutrient availability
Requires electricity and monitoring
More complex setup
Major differences side-by-side
Feature Kratky RDWC
System type Passive Active (recirculating)
Electricity ❌ None ✅ Required
Oxygen to roots Air gap (passive) Air pumps + circulation
Maintenance Very low Moderate to high
Cost Very cheap Expensive
Growth speed Moderate Fast
Yield potential Lower High
Risk of failure Low (few parts) Higher (pump failure, etc.)
Performance and use cases

Kratky is best for:

Beginners
Leafy greens (lettuce, spinach, herbs)
Small, low-cost setups
People who want minimal effort

RDWC is best for:

Experienced growers
Large plants (tomatoes, peppers, cannabis)
Maximizing growth rate and yield
Controlled indoor environments
Practical analogy
Kratky is like a plant living off a “static water tank.”
RDWC is like a constantly flowing, oxygen-rich river system.
Bottom line

If you want simple and low effort, go with Kratky.
If you want maximum growth and are okay managing equipment, RDWC is far more powerful.

[Szymon]

Hi Friends,

Here is an update on the RDWC setup. Over the weekend, I painted the wood with 2 coats of undercoat and 2 coats of a Fig Tree colour. The result matches the colour of the shelves I bought a month ago. Today, I cleaned all the pipes inside and outside, glued everything together, and added 2 more pipes with larger net cups. I'm waiting for that shipment to arrive, but it doesn't stop me from completing the project. The last part of this project is to make sure that the 6 taps are connected to the same-diameter hoses on the outflow back to the main holding tank, which is the big black box. I also need to connect the power points to the live power, and I think this project is done.

Here are the photos of the RDWC system.






2 more photos in the next post.

[Szymon]

Last two photos.




The next set of photos should show the RDWC in action with the water flowing. Also, when I finish both of the setups, I will do a cost analysis, and I can tell you straight away that it will be cheaper to do it yourself.

Cheers,
Szymon

[Szymon]

Hi Friends,

Here is an update regarding my RDWC hydroponics setup. As you can see, this setup is now finished. I got the water flowing. Everything is working as expected after a few little adjustments.


This is the air pump supplying the oxygen to the main reservoir.

Power still needs to be connected


As you can see, the netcup has water in it. It is only supposed to touch around 1 cm from the bottom.

Here are the outlet hoses.

See you in the next post.

[Szymon]

Here is the next lot.





Here are some more pictures of the RDWC setup.

Last night I placed 10 small green plants, 3-year-old packet seeds, into my seedling tray. These are Basil, Peppermint, and Rocket. I couldn't believe how small these seeds are.




This is how the seedling setup looks. The light timer is set from 6am to 9pm and switches off until the morning.

[Szymon]

Here is my last post. So this morning I took a look at the seedlings and already can see that there has been some progress from the Basil, on the left hand side.





I've highlighted in red.

Looks good.

Over the next few days, I will start setting up the Kratky method.

Cheers,
Szymon

[Harmony]

Thanks Szymon, wonderful to see your progress and the first little peek of plant growth. Hoping all goes well and we will see how the plants thrive along their journey, it must be quite exciting to see it all come together

[Szymon]

Posted by Harmony (here)
Thanks Szymon, wonderful to see your progress and the first little peek of plant growth. Hoping all goes well and we will see how the plants thrive along their journey, it must be quite exciting to see it all come together

Thanks, Harmony. Now the fun begins. Mixing the solution and making sure the EC and pH levels are top notch. Managing pests, algae, etc. I'm sure I'll have setbacks, but bit by bit I'll get there. I'll post my successes and failures as I go along. Cheers.

[Szymon]

Hi Friends,

Here is an update on my journey. I had mixed success with the old seedlings. I think the five-year-old seedlings are too old. At least I tried.




The tray with the sprouted peppermint already contains a half-strength solution. So this should speed up the process.



Today I've started a new tray with brand-new seedlings I bought a couple of weeks ago. I feel these ones will be much better. I also used cotton wool instead of rock wool.



I've learned a lot since I started and cannot wait to achieve some success.

Cheers,
Szymon

[Szymon]

Hi Friends,

Here is an update. Today I started using the Kratky method for growing. It's very simple. Get a food-grade black container with a lid. Drill some large holes in the lid to fit your net cups. Once done, fill it with the solution. Use a half-strength solution for your seedlings, and make sure the net cup is submerged by about 1 cm. The rest must be air so the seedling can breathe. I added an oxygen pump, but it's your call. Simple.

Below is my Kratky method setup.


Here are the hole markings just before cutting.


I've filled up 20 litres of half-strength solution.


Here are my pH and EC levels. PS - I haven't calibrated my meter yet and need to do this.


So, a total of 15 net cups, not bad for this 30-litre container.

Check out my next post.

[Szymon]

As you can see, for some reason, the 5-year-old Rocket seeds are working out very well.



I can already see Kale sprouting from the new seeds. Maybe it's the cotton balls as my growing medium?

I'll keep you guys updated.

Cheers,
Szymon

[Szymon]

Hi Guys,

Another quick update. The Kratky method seems to work. I'm going to use it for one more week before I put them into my RDWC system.



As you can see, the seedlings are starting to sprout now. I now have Kale, Rocket, and Basil, totalling 46 seedlings at various growing stages.



I'll keep you posted. Cheers.

[Szymon]

Hi Friends,

Here is an update. Overall, they are all growing very nicely. I haven't transplanted them to the big RDWC system yet. I still need to rewire the 15-amp heavy-duty power point to a household 10-amp socket. Hopefully, I should be able to finish that this week. I didn't expect to have a 15-amp socket. When done, it will power the RDWC system.

Anyway, here are some pics of the plants.



Parsley and Basil on the left-hand side, Kale and Rocket on the right-hand side.



Rocket, taking shape, the solution is at around 1.3EC, not even at full strength which should be at 2EC.




Here you can see the roots reaching all the way to the solution. Lifeline food supply.

Hopefully, I will get the big RDWC 70 Litre tank started soon.

Cheers,
Szymon

[Szymon]

Hi Friends,

Here is the latest. I still haven't fixed the PowerPoint. To do this, I need to switch off all the power in the house. Too busy with work at the moment.

Anyway, I've now placed almost all the plants in the net cups and increased the solution to 1.6 EC. The plants look healthy. Next stop: transplant them into the RDWC system, set the timer, and let nature do its thing.





Cheers,
Szymon

[Szymon]

Also, that last picture explains why Basil is super slow. It's been 20 days.

• Growth Rate: It is a fast-growing plant that can quickly grow quite large, sometimes reaching 3 feet in height.
  
• Growing Habit: It is a robust plant that can thrive and become quite bushy in pots or gardens, particularly when given plenty of sun and water.
  
• Starting from Seed: While some say the seeds can be slow to start, or that they are a bit slow for the first few weeks, they become fast growers once they establish and temperatures are above 60°F (15°C).

[Harmony]

Thanks for your udates Szymon.It really is difficult to grow Basil when it's cool or cold where you live. I often tend to grow grow rocket and English spinich for greens in the winter and then when the weather starts to warm again later in the year start lettuce and herbs and then the more cold sensitive things like tomatoes and zuccini's. The Brassicas like cabbage, broccoli, cauli, pak choy and rocket don't mind the chilly weather. You can check planting guides for your area like this one.


It's good to see your progress, thanks for sharing it all