The best thing to remember with harvesting is to be patient. A lot of people get too eager to harvest buds, and they end up taking their plants down too early. Wait for a few signs before you take the leap:
This is where your cannabis plants grow their fastest and drink heavily. They are also their sturdiest and most resilient to problems during this grow stage. The vegetative stage of cannabis growth is the easiest phase since all you have to do is replenish their water (with nutes included) and keep your lights adjusted.
Simply follow the included nutrient schedule or the custom nutrient schedules listed above (start at half strength and increase as needed) and keep the pH of your water between 5.5-6.5 at the plant roots for best results. Or feel free to use my custom DWC schedule for the GH trio [PDF].
In DWC, your plant roots are grown in a reservoir of aerated nutrient water that’s been adjusted to the correct pH. The roots are allowed to hang with only oxygenated nutrient water as a medium in order to get the best access to water, oxygen, and nutrients. This allows your plants to grow much faster as a result!
pH’ing Your Water:
After you’ve mixed all of your nutrients and supplements into your water, it’s important to ensure that the nutrient water is the correct pH so your plants are able to properly absorb nutrients.
Bubbleponics/Top-fed DWC is basically the same thing as DWC except for one small, but important, addition. A small stream of that same aerated, pH-balanced nutrient water is trickled over the young roots of your cannabis plants. This encourages the roots to grow faster and reach the reservoir water in less time, making for faster growth during the first part of the vegetative period.
Before You Start:
The aim is generally to try to get your cannabis to grow wide and flat like a table. However, you don’t want the plants to get crowded and end up having them compete for space, so it’s a good idea to make sure that each cola (main stem) has a few inches of open space around it.
Set your timer so that the lights are on for 12 hours a day. CFL bulbs with a color temp of
But for someone that has only grown in soil before there are some undeniable added new complexities to consider. You will need a, perhaps slightly noisy, air pump to feed the DWC air stone and you may need to discover the joy of owning and calibrating pH and EC meters for the first time.
Growing in a DWC cannabis system isn’t for everyone. But for those that do it well, dry yields of several hundred grams per plant are quite routine. Deep water culture cannabis growing pushes hydroponics (soil-free) cultivation to it’s limits. As such, it’s the ultimate thrill and ultimate challenge for many indoor growers. For those that truly enjoy their cannabis cultivation there are few more satisfying feelings than seeing a crop grow from seed to harvest. When you harvest your first DWC monster the joy and satisfaction will be remembered forever.
Many serious growers change the nutrient bath at fixed schedules, often weekly. You may be able to leave your nutrient bath 1-2 weeks between changes in veg. But in bloom, with hungry plants you should aim for complete weekly nutrient bath changes at a minimum. Pro growers may change baths even more frequently than that. They will check their baths once or twice a day in late bloom, topping up with nutrients.
The benefits of growing cannabis with DWC
Deep Water Culture (DWC) is the technique of growing cannabis plants with their roots growing in a bubbling (aerated) nutrient bath. Growing cannabis in a DWC system is claimed by many to be the fastest way to grow heavy yielding cannabis plants. However, the technical complexity of correctly maintaining the pH and concentration of the nutrients does place certain requirements on the grower. DWC cannabis growing offers great rewards, but it is far from the easiest grow technique to master.
The main attractions of growing DWC cannabis are the fast growth rates and huge yields that are potentially on offer when DWC is done well. For those that delight in the joy of growing their own cannabis, there is an undeniable satisfaction that comes from seeing a successful DWC grow really push the cannabis plant right to it’s limits.
A DWC cannabis grow comes in many different styles and adaptations. However the common theme is that the roots are immersed in a bath of nutrients at an optimum pH, often around pH 5.8. Normally cannabis roots left in water/nutrients would eventually rot. But the presence of bubbling air (e.g. from a DWC air stone, connected to an external air pump) provides the roots the oxygen they need to grow with great vigour.
Growing cannabis in DWC system
The container is often simply a deep bucket (hence the name, DWC) which is often black in colour. The absence of light keeps dreaded slime and algae to a minimum. One plant can comfortably fill the typical 15-20 litre DWC bucket full of cannabis roots by the end of the grow. A healthy root ball is a huge white mass of roots.
Above the root-zone the plant grows normally, though with enhanced speed and yield thanks to the optimised conditions in the root area. The nutrient bath will need replacing frequently, especially as the plants mature. As with other grow methods, the nutrients tend to slowly increase in strength as the plant develops.