What Double Barrel Means on the Under Current Double Barrel 16
Double Barrel is the row count. The standard Under Current runs two rows; this one runs four, feeding all of them from a single continuously recirculating solution. More canopy sits on the same aisle structure, and there is still only one reservoir to read and correct. Sixteen sites, four rows, 200 gallons total volume. XXL13 names the spacing and module pairing. That means 13 gallon Blackout Series modules set on 40 in centers, the widest layout Current Culture offers in this line.
Sizing a Room Around a 16 Site RDWC System
Current Culture puts the system footprint at 12 ft 10 in by 14 ft 2.5 in. Around it they recommend an 18 x 20 ft grow area. That gap is aisle, and it is not optional on a 16 site rdwc system you have to walk. Lighting works out to 16 x 600W horizontal or 21 x 600W vertical. A 1/2 to 1 HP chiller handles the water, though final sizing follows the chiller maker rather than this page. The 1,200 GPH Mag-Drive turns the full volume over roughly six times an hour. Veg runs 4 to 6 weeks to a 30 to 36 in plant before flip. The honest note on 40 in centers: it is generous spacing, so this is the layout for fewer, larger plants rather than a dense turn. If you want the same 16 sites tighter, the XL13 version drops to 30 in.
Key Features
- Four rows, one shared solution: Double Barrel doubles the row count over the standard Under Current, still on a single reservoir.
- 16 sites at 40 in centers: XXL13 spacing built for fewer, larger plants and a longer veg.
- 13 gallon Blackout Series modules: 200 gallons total system volume, recirculating continuously.
- 12 ft 10 in x 14 ft 2.5 in footprint: Plan an 18 x 20 ft room around it so the aisles stay walkable.
- 1,200 GPH Danner Mag-Drive return: Turns the full system volume over roughly six times per hour.
Technical Specifications
| Specification | Value |
|---|---|
| Model | UCDB16XXL13, Under Current Double Barrel XXL13 |
| Number of Rows | 4 |
| Number of Sites | 16 |
| Plant Spacing | 40 in centers |
| Module Size | 13 Gallon Blackout Series |
| System Footprint | 12 ft 10 in x 14 ft 2.5 in (3.91 m x 4.33 m) |
| Total System Volume | 200 gal / 758 L |
| Water Pump | 1,200 GPH / 4,543 LPH Danner Mag-Drive |
| Recirculation Rate | Approx 6.3 exchanges per hour |
| Recommended Grow Area | 18 ft x 20 ft (5.49 m x 6.1 m) |
| Lighting - Horizontal | 16 x 600W |
| Lighting - Vertical | 21 x 600W |
| Chiller Size | 1/2 to 1 HP (confirm with chiller manufacturer) |
| Reservoir | 200 gal / 800 L |
| Veg Time | 4-6 weeks to 30-36 in |
| Warranty | 1 year |
What Ships With the System
- 13 Gallon Blackout Series growth modules, with CCH2O 8 in heavy duty lids and net pots.
- 3 in manifold and joints with 3 in UC Spin-Tight bulkheads, plus a Danner Mag-Drive return pump.
- Premium linear air pumps, 9 in air diffuser disc, Aqua-Pore air diffusers, air distribution manifold, air hose and in-line filters.
- Adjustable float valve with reservoir adapter kit, drain valve, chiller adapter and garden hose drain adapter.
- Cultured Solutions VEG A/B, and a 1-year warranty.