The Rise Of The Bubbler!

22-02-2012 - Grow with Little Lebowski
DWC grown bud... ready for harvest!

Deep Water Culture (DWC) has seen a real surge in popularity in certain areas of the UK with word of mouth spreading amongst growers, more and more cannabis cultivators are moving from pots and soil onto the bubbler system. Lots of hydro retailers are putting together systems that are simple to use, cheap to set up and operate and produce BIG results.

Put simply, Deep Water Culture is a growing method whereby the roots of the plant are constantly submerged in a highly oxygenated nutrient solution (hence the term; ‘Deep Water'). Very little growing medium is used, other than a propagation cube and a few clay pebbles. The initial root ball of the plant is started in a net pot, suspended above a reservoir or bucket. The roots of the plant grow out of the pot and into the reservoir where there is constant availability of water, nutrient and oxygen; delivered via an air pump.

The roots of the plant are constantly submerged in a highly oxygenated nutrient solution

Deep Water Culture is most commonly used to grow plants full cycle, but can also produce great results when used to propagate clones.

Plants that are grown in Deep Water Culture have constant access to nutrient solution and oxygen; taking up much more water and nutrients than plants that are hand watered. The more oxygen, water and nutrients that a plant can absorb, the more bud they will produce.

Why Use Deep Water Culture Instead Of Pots And Soil?

  • Simplicity - most systems are built of just four main components; a reservoir, a lid, a net pot and an air pump. There are no moving parts and, usually, no external pipework - so no possibility of leaks.
  • Bigger yields - DWC systems offer massive exposure of the plants roots to water, nutrient and oxygen. The more of these three key elements that the plant can uptake, the faster it will develop, the bigger it will grow and the more it will potentially yield.
  • More crops per year - plants grown in DWC develop very rapidly, which allows growers to shorten the vegetative period of their growth cycle and get more harvests in per year.
  • No soil - no heavy bags to carry in and out of the house, no messy potting up stage and no risk of soil borne pests and disease.
  • No feeding schedules to work out - plant roots have constant exposure to all of the water and nutrient they require, they uptake whatever they need, exactly when they need it. No timers required.
DWC systems are basic and easy to set up; there are no timers or feeding schedules to calculate

What Types of Deep Water Culture Systems Are Available?

Bucket systems
The most common and readily available form of DWC system, often known as oxy pots or bubbler buckets; these consist of a 20L black bucket with a net pot moulded into the lid and an air pump. The plant is placed into the net pot along with some clay pebbles; the bucket is filled with nutrient solution until the level is a couple of inches under the base of the net pot, this forms the reservoir that the plant feeds from. Air stones are attached to the bottom of the tanks with suckers and the pump is left on 24 hours a day.

The bucket needs to be black to ensure that no light can penetrate the root zone, as light damages the roots. After a few day the moist atmosphere in the bucket will encourage the roots to grow out of the pot and down into the oxygen rich, nutrient solution - although most growers will prefer to give some water from above, just to make sure that the roots don't dry out before they hit the reservoir.

Bucket systems are great for growers who want to get big yields off a few large plants. Each bucket fits a single plant into it and, because the buckets aren't connected to each other, they can be moved around individually. Another advantage is that the plants aren't sharing the same reservoir, so if one plant gets root problems, like pythium, you don't lose your entire crop.

DWC Cloners

A high quality air pump is the heart of a DWC system

Usually consist of a tray or a bucket that is filled with water to create a small reservoir, air stones are placed in the reservoir and clones are held upright in a tray - using neoprene clone collars - that sits on top of the reservoir. The stems of the clones are suspended underneath the tray, just above the level of water. When the air pump is turned on, the ‘bubbling' effect in the reservoir creates a moist, humid atmosphere in the root zone.

This humid atmosphere, combined with the lack of restrictive growing medium, encourages roots to develop rapidly from the stem of the clone.

Growers can benefit from a much improved success rate, as the lack of growing medium used means the propagation environment is kept sterile and the fast root development allows you to get your grow started earlier.

DIY Bubbler Systems
For the grower that enjoys to put their own set up together, DWC provides a great option. All your need is a reservoir, a lid, some net pots and an air pump with air stones. Plastic storage boxes are available from most supermarkets or DIY centres and create a ready-made reservoir and lid, just make sure that they are a dark colour so that light cannot penetrate the root zone.

Simply drill holes into the lid and file them out so that they fit the net pots. Use air stones or soaker hose to aerate the reservoir. Soaker hose is a great option for larger tanks as it creates a ‘wall of bubbles' that covers a larger area than a single air stone.

The benefit of building your own bubbler system is that you can space out the plants how you want; grow one or two big plants in the system or put lots of plants close together in system and grow a sea of green.

Hybrid Systems
These are becoming more and more popular amongst growers who have had successful crops using bubbler systems and are now refining the technique. The hybrid system uses a drip ring to feed from above whilst also utilising the DWC technique. Instead of using net pots like in a bucket or DIY system, the plants are placed in a deep tray, or planter, with holes drilled in the base. The planter sits above the reservoir.

The young plant is placed in the planter, which is then filled with clay pebbles. Air stones are placed in the reservoir below. A water pump delivers nutrient solution from the reservoir out of the drip ring and over the roots of the plant. The roots grow down amongst the clay pebbles, through the holes in the bottom of the planter and into the aerated reservoir below.

The hybrid system offers several benefits over a regular DWC system;

  • the drip ring feeds the plant before the roots hit the reservoir, so there's no need to hand water from above when the plant first goes into the system
  • only half of the plant roots are in the reservoir, this reduces the risk of root borne diseases that can sometimes occur in DWC
  • the plant is fed using a water pump and an air pump, giving growers extra insurance over pump failures; if one pump breaks the roots will still receive nutrient solution
  • faster veg time; there's no delay in the plant getting established in the system because the plant is fed by the drip ring before the roots hit the reservoir
  • bigger yields; the dual feeding means that the plant is getting the optimum amount of water, nutrient and oxygen

Hybrid systems are also known as ‘bubbleponics' in certain areas of the UK.


What Type Of Grower Is Using DWC?

  • Beginners or growers who haven't used hydro before. DWC systems are basic and easy to set up; there are no timers or feeding schedules to calculate.
  • Percy growers looking to get a big yield off one or two plants in a small grow room.
  • Aeroponic propagator users, as their bare rooted cuttings can be transplanted directly into the system and will ‘take' almost immediately, with little risk of transplant shock.
  • Growers who do not have the facility to dispose of lots of soil or coco. The only growing media used is propagation cubes and a few clay pebbles. There are no bags of waste to throw away after you harvest, just a bucket of roots!
  • Commercial growers looking to cut down on the number of plants they cultivate. Plants grown in DWC can get big, quickly.

Deep Water Culture Top Tips

1. Invest in some decent EC and a PH meters. There is no buffer around the roots in a DWC system, so the strength and PH of the nutrient solution must be constantly maintained.

2. Leave the pump on 24/7. To get results in DWC, the air pump must be left on constantly. A plant's roots need constant access to water, nutrient and - most importantly in DWC - oxygen. Remember that DWC is a ‘bare rooted' technique and the roots are constantly submerged. Turning off the pump, even for a short period, can damage them.

DWC cloners propagate clones rapidly
Flo Gro systems make the ideal hybrid growing system


3. Make sure that your starting EC is low; it's easy to overfeed in DWC. Remember that the nutrient solution is the growing medium; there is no ‘buffer' between the roots and the food. Any mistakes in dosage can potentially damage the plant and there is no medium to flush through. If you overdose on nutrients, you'll need to change all the solution in the reservoir.

4. Only use mineral nutrients and additives. Organic feeds and supplements aren't suitable for DWC; the liquids will spoil in the reservoir after a few days and can, potentially, damage the roots.

5. Keep your grow room temperatures in check. Any temperature fluctuations in the grow room will directly affect the roots of a plant grown in DWC. Use a heater in the winter to raise the night time temperatures and increase the size of your extraction fan in the warmer months to reduce the temperature in the grow room. The optimum root temperature to maintain is 18°c - 22°c.

6. Transfer at the right time. Growers that use an aeroponic (or DWC) cloner can transplant as soon as the roots are three or four inches long. Take the cutting out of the cloner and place it into the net pot of the DWC system, using clay pebbles to hold the young plant in place. Take extra care when handling the roots as any broken or damaged roots are susceptible to attack from pathogens. By using a cloner, and not having to wait for a cutting to root out into a propagation block, you can cut the veg period by a good few days. If plants have been started in a propagation medium like rock wool cubes, then they are ready to transfer into the system as soon as the outside of the medium is covered in white roots. If you transfer before white roots are visible, then the roots in the cube can become saturated and starved of oxygen.

DWC bubbler bucket

7. Only use an inert growing media, like rock wool and clay pebbles. If you transplant from soil or coco, the media will break down and could block the pump. You also run the risk of introducing soil borne pathogens into a ‘bare rooted' environment.

8. Space plants out taking into consideration the faster growth expected. The water within the reservoir will act as a support for the roots - although the plant won't be as stable as it would in soil or coco - there is no immediate need for plant supports - like there is in NFT or aeroponics. But, considering the big yields experienced in DWC; pea netting, roller hooks or yoyos may well be needed to support those monster buds!

Happy Bubbling!


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