Growrilla Hydroponic system 2.0 RDWC 2

The smallest system Growrilla makes: two pots, one row, and enough hardware to learn hydroponics without setting up a whole grow room for it.

The Growrilla Hydroponic System 2.0 RDWC 2 is for the grower moving away from soil or coco who wants to find out what all the talk about hydro is actually about. Two 19-litre pots, a controller pot between them, and 45 litres of nutrient solution circulating continuously. It takes up 80 by 65 centimetres, so it fits an 80 by 80 tent or sits along the long side of a 120 by 60.

Starting small with hydroponics is not a bad move. Everything you learn here about correcting EC, topping up and reading roots applies directly to a system of eight or twelve pots later. The difference is that a mistake here costs two plants instead of twelve.

What deep water culture actually is

In DWC (deep water culture) the plant sits in a net pot holding a handful of clay pebbles, and the roots hang straight down into the nutrient solution. No soil, no coco, no substrate holding moisture. Just water with exactly what the plant needs dissolved in it.

That sounds like drowning, and it would be if nothing else happened. The difference is the air stone at the bottom of every pot. It pushes a constant stream of fine bubbles through the solution, and those bubbles do two jobs: they put oxygen into the water, and they keep the whole volume moving so no dead zone forms where the water sits still.

Roots suspended in permanently oxygenated water have nothing to search for. No dry pockets in the pot, no competition with soil life, no waiting for the next watering. Everything is present, all the time, at exactly the concentration you set. That is where the growth rates hydroponics is known for come from, and equally why it goes wrong the moment aeration falters.

Why recirculating beats separate buckets

You can run DWC with two loose buckets and an air stone in each. It works, and it is cheaper. But then you have two separate systems.

Each bucket develops its own EC, because one plant drinks harder than the other. Each develops its own pH, because that moves with uptake. You measure twice, correct twice and top up twice. With two buckets that is manageable. With six it becomes a daily job, which is precisely why people give up on it.

The R in RDWC stands for recirculating. The pots are joined by 32 mm pipework, and a pump in the controller pot keeps the solution moving through all of them. That turns two buckets into one 45-litre reservoir that happens to be spread across three containers. One measurement, one correction, one top-up, and both plants get exactly the same thing.

That principle is the entire reason these systems exist, and it gets more valuable with every pot you add. At two pots it saves you effort. At twelve it is the difference between practical and not.

What you still need to supply

The system gives you the pots, the pipework and the pumps. The rest is on you:

• An EC and pH meter. Not optional. In hydroponics the solution is all the plant has, and you cannot tell what is in it by looking.
• pH down for corrections. Acidity drifts during a grow; you steer it back.
• Nutrients made for hydroponics. Soil nutrients will not behave the way you want here.
• Clay pebbles to fill the net pots.

Allow about fifteen minutes to build. The joints are push-fit: press until they seat, no tools and no glue.

Technical Specifications:

• System type: RDWC recirculating hydroponic system
• Growing pots: 2 x 19 litre (Ø 30 x h 33 cm)
• System rows: 1
• System water volume: 45 litre
• Plant spacing: 50 cm
• System footprint: 80 x 65 cm
• Recommended growing area: 80 x 80 cm or 120 x 60 cm
• System power: 17 watt
• Air pump: Hailea ACO9602 (7.2 L/min)
• Water pump: Hailea HX2500 (650 L/h)

Frequently asked questions

Is this suitable if I have never grown hydroponically?
Yes, and that is what it is for. Two plants are manageable, 45 litres mixes in one go, and 17 watt is not something you will notice on your bill. What you learn here transfers to any larger system.

Can I expand it later?
The pipework comes apart by hand, so adding pots is possible. Watch the pumps though: the ACO9602 and the HX2500 are sized for two pots. Moving towards four or six means heavier hardware.

How often should I change the solution?
A full change every one to two weeks is a common schedule. At 45 litres that is one bucket to empty and remix. One of the few things genuinely easier at this size than on a large system.

What happens during a power cut?
The water pump stops and so does aeration. A few hours is survivable; there is still dissolved oxygen in the solution. Beyond half a day it gets critical, because oxygen runs out in standing water and roots start to rot.

Can light reach the solution?
No, and that is deliberate. The pots are double-walled: black inside so no light reaches the water and no algae can grow, white outside so heat from your lamp is reflected away instead of absorbed.