Before we get into the nitty gritty details, let’s get a high-level overview of this type of system. In a DWC system, a plant’s roots are suspended in a well-oxygenated solution composed of water and nutrients.
There are three critical parts of this solution:
· Oxygen: Because the roots are submerged in water and not soil (which has gaps and holes where air resides), the water needs to be well oxygenated so the plant doesn’t drown. This is accomplished with an air pump and air stone.
· Water: Think of this system as if you’re growing in soil and permanently watering your plants – this is one of the reasons growing hydroponically is so beneficial – you never need to ‘water’ again.
· Nutrients: A good quality soil contains all of the micro and macro nutrients that a plant needs to survive and thrive. Because we have no soil, we need to supplement the oxygen-rich water with nutrients so our plants can grow.
This method is called Deep Water Culture for two reasons. One, you typically grow with a reservoir that can hold a decent amount of water. More water means more stability in your nutrient solution, which means less monitoring and maintenance for you!
The second reason is because of how much of the root mass you submerge in the water. Other methods expose your plant’s root zone to air and drench them in water just a few times a day (ebb and flow systems are a good example of this). In deep water culture, most of your plant’s root system is submerged 24/7 – hence the name!
DWC systems are popular for many different reasons, the primary one being that they’re one of the simplest types of systems to start with. The only system that is simpler is a wicking system.
Here are a few other benefits to growing in a DWC system:
· Very low maintenance once you set it up
· Extremely fast growing time compared to soil (I’ve grown lettuce to harvest in 30 days instead of 60 in soil)
· Very little moving parts and assembly
However, it’s not all sunshine and roses. There are some issues with this type of system that can cause you problems. These are mostly avoidable if you’re maintaining your garden, though:
· In small systems, pH, water level, and nutrient concentration may fluctuate wildly
· In small systems, opportunity to over or undercalibrate is VERY easy due to small scale
· If you have an electricity outage or a pump failure, your roots may “drown” in low-oxygen nutrient solution
· It can be difficult to maintain a consistent water temperature
Traditional DWCs are the easiest to build. Here’s a list of the parts you’ll need to set up your first system:
· 5-gallon bucket
· Air pump
· Air stone
· Airline tubing
· Net pots
· Growing media
· Hydroponic nutrients
· pH control kit
· PPM meter
The method is simple: connect the pump to the tubing, the tubing to the air stone, and place the air stone in the bucket. Fill up the bucket with water, properly pH and add your nutrients, and start your seeds. (Both of those links are to great videos that go into a lot more depth!)
Once your plants start to germinate and the roots start to hit the water, you’ll see an explosion of growth. Instead of spending energy growing the roots to search for pockets of water in soil, your plants can simply suck up as much water and nutrients as they need right away.
If the water is properly oxygenated, there’s no reason why your plant’s roots can’t remain submerged deep in the water (hence the name) for the entire life cycle of the plant!.
Because of the highly oxygenated and nutrient-rich solution, plants grown in a traditional DWC system can be harvested up to twice as fast as normal soil-grown plants! I’ve personally harvested a head of lettuce in 30 days from germination
The fastest I’ve ever grown lettuce in soil is 60 days.
The traditional method is amazing for beginners, but what if you want to scale your system to the next level? Most people move to a RDWC, or Recirculating Deep Water Culture system when they want to upgrade their garden.
If you’re looking to grow at scale, the last thing you want to do is have 10 individual buckets, all requiring their own calibration and adjustment. If you’re growing the same plant across 10 different buckets, doesn’t it make a lot of sense to have one main reservoir and feed that nutrient solution across all 10 buckets?
If you said yes…you just invented the RDWC system!
You’d have to have a love of torturing yourself to want to individually pH and calibrate each of these buckets!
You might be wondering how the oxygenation of the water occurs if you have multiple buckets chained together. Just as it would be inefficient to have separate nutrient solutions for each bucket, it’s also inefficient to run an air stone system for each bucket.
This is where the recirculating part of the name comes into play. As water moves from bucket to bucket, it’s shuttled around via spray nozzles that oxygenate the water.
The beauty of this modification to the classic DWC system is that you only have to calibrate, oxygenate, and add more water from one central location and it gets fed out to all buckets immediately. The best analogy here is the power grid: we don’t run our own generators in our homes. Power is generated from centralized locations and then ‘sent out’ through the power grid to our houses.
Although many people don’t consider Bubbleponics to be all that different that the traditional DWC, I personally think that it has a few advantages and is important enough to talk about. Despite its silly name, the adaptation that Bubbleponics makes is simple.
Instead of waiting for your plants to germinate and the roots to hit the top of the water in your reservoir, Bubbleponics aims to speed up that process by top-feeding the nutrient solution to your plants for the first few weeks.
All that’s going on here is the addition of a water pump to the system, with drip lines running up out of the tank to the net pots that your plants are sitting in. Simple, but very effective in speeding up the germination and seedling phase of a plant’s life cycle.
