Growrilla Hydroponic system 2.0 RDWC 8

Eight pots on exactly the same pumps as the six-pot system, at the same power draw. On paper the best value point in the whole range.

Anyone moving from the RDWC 6 to the Growrilla Hydroponic System 2.0 RDWC 8 expects everything to scale up: more pots, heavier pumps, higher consumption. That does not happen here. You get two more pots, but the same V30 air pump, the same HR1000 water pump and the same 52 watt. Two extra plants cost you nothing in hardware and nothing in electricity.

And the extra thirty litres of solution work in your favour. That sounds contradictory (more water looks like more work) but the opposite is true.

Why a bigger reservoir is easier, not harder

Everything that goes wrong in a hydroponic system goes wrong because a value drifts: EC creeps up because plants take more water than nutrient, pH falls, temperature rises. The smaller the water volume, the faster that happens.

In 45 litres you notice a mistake within a day. In this system's 135 litres you have room. Forget to top up for a day and it is something to note rather than an emergency. Get your nutrient mix wrong once and it dilutes across a large volume instead of showing up on the leaves immediately.

So eight plants on this system do not demand more attention than six. If anything, less.

Water temperature: this is what actually goes wrong

When an RDWC system fails, it is almost never the pump and almost never the nutrients. It is the temperature of the water.

Warm water holds less oxygen. That is straightforward physics, and it bites harder than most growers expect. At the same time, root rot pathogens like Pythium thrive in warm, oxygen-poor water. The two effects reinforce each other: the warmer it gets, the less oxygen there is and the more active the pathogen becomes. That is why a system running perfectly for weeks can still collapse during one warm spell.

The double-walled pots already help here: black inside so no light reaches the solution and no algae can form, white outside to reflect your lamp's heat away rather than absorb it. If the room still runs warm, the controller pot has two fittings a water chiller connects straight onto.

Measure water temperature, not air temperature. The two diverge further than you would think.

The layout

Two rows of four at 50 centimetre centres, 80 by 205 centimetres in total. That is a long, narrow run that lands almost exactly on a 240 by 120 tent, with the controller pot at the end where you can get to it easily.

The advantage of that shape only becomes obvious once you work with it: with two rows you are never more than one pot away from wherever you need to be. On the larger systems with three or four rows you have to reach across pots. If you want it shorter, slide the pots closer together along the 32 mm pipework: the spacing is not fixed.

Built in four steps

1. Lay out the pipework and position the pots. Everything is push-fit: press until it seats, no tools and no glue.
2. Put the controller pot at the end of the run, somewhere you can genuinely reach once the system is full.
3. Hang an air stone in every pot and distribute the tubing from the V30.
4. Fill with water, run it for an hour and check for leaks before any plants go in. Only then mix nutrients and set EC and pH.

Allow half an hour to build, and five minutes to take apart.

Technical Specifications:

• System type: RDWC recirculating hydroponic system
• Growing pots: 8 x 19 litre (Ø 30 x h 33 cm)
• System rows: 2
• System water volume: 135 litre
• Plant spacing: 50 cm
• System footprint: 80 x 205 cm
• Recommended growing area: 240 x 120 cm
• System power: 52 watt
• Air pump: Hailea V30 (30 L/min, 1800 L/h)
• Water pump: Hailea HR1000 (1050 L/h)

Frequently asked questions

Does this fit a 240 by 120 tent?
Yes, the 80 by 205 centimetre footprint is built around it, and you keep working room on every side. It will also go into a 200 by 100 tent if you slide the pots slightly closer together.

Can I expand to more pots later?
The pipework comes apart by hand, so adding pots is possible. Mind the pumps though: the V30 and HR1000 are sized for eight pots. Heading towards twelve means heavier hardware.

How much water does a system like this use?
In full flower eight plants will readily take 10 to 20 litres a day. Top up with water at the correct EC rather than plain water, otherwise your nutrient concentration climbs while you believe you are diluting it.

Do I need a water chiller?
Not as standard. If your water stays below 22 °C you will manage without. Above that, a chiller is the cheapest insurance available, and the fittings are already there.

Why eight rather than six?
Because nothing changes between them except the number of pots. Same pumps, same power draw, more plants and a larger, more stable water volume. The only question is whether you can accommodate 205 centimetres of length.