The patented Under Current RDWC Hydroponics System is recognized as the gold standard for hydroponic crop production.
The most proven and widely utilized Recirculating Deep Water Culture hydroponic system in the world, the Under Current is renowned for producing the very highest quality fruits, flowers, and essential oil profiles.
What's Included:
Pleave view the Assembly Instructions PDF for a list of included parts.
Feautres & Benefits
The Under Current features the patented Sub-Current Culture circulation method. This high-performance water culture system is unmatched in efficiency, layout versatility, and ease of use. The Under Current utilizes negative water pressure to recirculate oxygenated nutrient solution through the plant's root zone ensuring pH and EC levels are uniform throughout the entire system.
- Grow Trees: Yield more with less. Reduce plant counts. More production per plant
- Get Your Weight: Accelerated growth rates. Cut veg times. Heavy yields = heavy profits
- Take A Vacation: Easy and reliable. No timers, no guesswork. Reduce labor & maintenance
- Top-Shelf Results: Optimal Resin Output. Strong Terpene Profiles.
- Craft Cultivation: Ideal For Artisinal Batch Cultivation
- Facility Proven: Trusted By Professional Growers Worldwide
This unique, high-performance water culture system utilizes negative water pressure to recirculate oxygenated nutrient solution through the plant’s root zone. Requiring no timers, the 24/7 circulation and aeration encourage rapid root growth and ensure pH and EC levels are uniform throughout the entire system.
Highly regarded for its unparalleled growth rates and record-setting yields, the Under Current is simple to operate and well-suited for residential, professional, and commercial facility applications.
Compare the Under Current Systems
Under Current
- 8 Gallon Mods
- 18" Spacing
Under Current XL
- 8 Gallon Mods
- 25" Spacing
Under Current XL13
- 13 Gallon Mods
- 30" Spacing
Under Current XXL13
- 13 Gallon Mods
- 40" Spacing
Optional Add-Ons for Current Culture UC Systems
Cultured Solutions Nutrients & Clear Line Hypochlorous Acid
Cultured Solutions liquid fertilizers were originally developed for precision irrigation applications such as Aeroponics, RDWC, and pressure-compensated drip. These productive methods all require an exceptionally clean nutrient formulation to operate properly.
Clear Line is designed to keep drip irrigation lines and emitters clean and free of mineral deposits during cropping cycles. Implementation of Clear Line by Cultured Solutions protects drip irrigation systems reducing costly repair and replacement of components.
Verdera Mycostop is a biological fungicide that helps to prevent & supress damaging diseases. It contains the mycelium and spores of Streptomyces Strain K61, a naturally occurring bacterium derived from Sphagnum peat. It thrives in the root zone and controls some of the most destructive plant pathogens.
Hydro Frost Solution Chillers
Hydro Frost Solution Chillers provide precise temperature control for irrigation reservoirs and hydroponic systems. Utilizing commercial-grade components and solid-state electronics, these chillers deliver reliable performance and are built to last for years. Hydro Frost Solution Chillers integrate seamlessly into a wide range of irrigation applications. These durable units provide a reliable solution for controlling nutrient solution temperatures, ensuring optimal crop performance.
Nuravine automated systems provide the dosing, monitoring, and valve control necessary to automate processes and reduce associated labor and inconsistency. The Aurora bundle presents accurate readings of pH, EC, temperature, dissolved oxygen, and ORP levels.
| Brand | Current Culture |
|---|---|
| SKU | UC12-SINGLE-5.5 |
| Weight (lb.) | 140.0000 |
| Prop 65 | false |
| Hazardous Material | false |
| UPC | 697691621081 |
| Lead Time | This product ships in 1 week |
| ETL Listed | No |
| Plant Count | 12 |
| Growth Module Size | 8 Gallon |
| Number of Rows | 2 Rows |
| Total System Volume | 88 Gallons |
| Recommended Reservoir Size | 100 Gallon |
| Recommended Chiller Size | 1/4 - 1/2 HP |
| System Footprint | 2'10.5" x 11'4.5" |
| Exact Watts | 130 Watts |
Current Culture Under Current UC RDWC System, 12-Site, 2-Row Videos
Current Culture Under Current UC RDWC System, 12-Site, 2-Row Questions & Answers
General Recommendations
What are the most common mistakes made in water culture?
a. Running nutrient strength too high. This can inhibit water uptake and contribute to metabolic stagnation and subsequent plant stress.
b. Using incompatible inputs in solution causing convolution of the water chemistry. Avoiding organic, low solubility inputs is strongly recommended.
c. Micromanaging pH. Adjusting pH too frequently can lead to nutrient solution instability and issues.
What makes the Under Current a more efficient hydroponic method?
Less frequent nutrient change outs, lower nutrient usage rates, less pH fluctuations (less pH adjusters needed) and the conservation of precious H2O.
What makes the Under Current more productive compared to other hydroponic systems?
When a water culture system is operated properly, plants benefit from an increased uptake of water and minerals in solution as well as sustained cell turgidity. Given the favorable CEC of water, a plants nutrient uptake efficiency in water culture is very high, resulting in superior results.
Planning And Sizing
What is the approximate volume of solution in each module during standard operation?
a. 8 gallon – approx. 6 gallons
b. 13 gallon – approx. 10 gallons
c. 35 gallon – approx. 30 gallons
How do I calculate my total system volume?
a. Multiple total number of modules plus 1 (for Epicenter) multiplied by the approximate volume per module. Take this volume and add 10% to account for solution in joints and manifolds.
b. Example: UCDB16XL –
i. 17 x 6 gallons per module = 102 gallons
ii. 102 + 10% = 112 gallons
Can I integrate a nutrient auto dosing system?
Yes.
What is a top-off reservoir and why do I need one?
A top-off reservoir is used to maintain consistent system volume and water chemistry. The top-off reservoir will supply solution via gravity to the float valve in Epicenter (control module).
Do I need a water chiller?
Yes.
Do I need a Bulkhead Filter for each growth module?
No.
Is there an option for custom system spacing?
Yes, all systems are available in a “Boneless” configuration without straight sections of pipe, allowing you to customize your plant centers.
Does a "Boneless" system include instructions on how to cut/couple pipe?
Yes, each “Boneless” kit includes a Boneless cut chart and recommendations for gluing and assembly.
Operating the Under Current
Should the Air Pump and Water Pump run 24/7?
Yes.
Where should I set my solution level?
a. Initial Transplant: See diagram.
b. Veg: 2” above base of net pot.
c. Bloom: 1” below base of net pot
What should be in my top-off reservoir?
When operated properly, top off should be balanced the same or slightly higher as the solution in the system.
Does a top-off reservoir help maintain water chemistry (pH/EC) stability?
Yes. Any fluctuations in pH/EC can have a negative effect on plant health.
How do I adjust pH?
a. CAUTION: Do NOT add pH concentrate directly to Epicenter (control module).
b. If the pH is between 5.5-6.5 no adjustment is necessary.
c. Dilute pH adjuster 1:128 (about 1 oz. adjuster per gallon of fresh water). Once diluted slowly add to the system, allow 20-30 minutes for mixing. Re-test once pH has stabilized, add more diluted adjuster as necessary.
What solution temperatures are optimal?
We recommend maintaining a water temperature between 65-68 degrees F.
What solution temperatures are optimal?
We recommend maintaining a water temperature between 65-68 degrees F.
Do I need to include the initial PPM of my source-water when calculating nutrient levels?
Yes. Adjust accordingly.
Do I need to include the initial PPM of my source-water when calculating nutrient levels?
Yes. Adjust accordingly.
Do I have to empty out the entire system to do a nutrient change-out?
No.
What do I use to clean the system? Mix Ratio of Cleaning Agent?
Physan 20, follow manufacturer’s directions.
Growing in the Under Current
How do you veg for the system?
a. Under Current system (8 gallons): Bare root or cube (rock wool, oasis, etc) propagated plants can be placed directly into our CCH2O Net Pot and placed directly into a Under Current system for optimum growth. This technique is perfect if subsequently transplanting into a larger Under Current system (13 gallon or 35 gallon PRO) at a wider plant spacing.
i. In this case, the entire CCH2O Lid (with Net Pot) can be picked up and moved directly to another Under Current growth module for flowering. This method is ideal for avoiding unnecessary root damage during transplant into bloom.
b. Ebb and Flow table (Periodic Flood): Bare root or cube (rock wool, oasis, etc) propagated plants can be placed directly into our CCH2O Net Pot or 4″/6″ rock wool cubes and placed in a typical tray. Some natural root pruning may occur as the roots grow through the net pot due to the intermittent watering cycle.
c. Ebb and Flow Table (Continuous Flood): Bare root or cube (rock wool, oasis, etc) propagated plants can be placed directly into our CCH2O Net Pot or 4″/6″ rock wool cubes and placed in a typical tray. Adding air diffuser to the tray will create a water culture environment. This will stimulate root growth similar to the Under Current system and prepare the plants for a fairly seamless transition.
d. Drip: Bare root or cube (rock wool, oasis, etc) propagated plants can be placed directly into our CCH2O Net Pot or 4″/6″ rock wool cubes. A drip system with emitters in each net pot/cube can be placed on a bench or in a flood tray. Some natural root pruning may occur as the roots grow through the RW cube.
What grow mediums are recommended for use in the Under Current?
a. Any non-wicking inert grow media tends to work best. Expanded clay pellets and growstones are some of the most popular.
b. When using a wicking media like rockwool be sure to adjust solution level to ¼” below contact with the R.W.
Nutrient Considerations
What is the best nutrient for the Under Current?
Pure mineral-salt based nutrients like Current Culture’s Cultured Solutions are the most compatible with actively aerated water culture.
What is the recommended nutrient strength for the Under Current?
a. Veg: 100-400 ppm / 0.2-0.8 EC
b. Bloom: 450-900 ppm / 0.9-1.3 EC
c. **Based on ppm 500 scale
Are carbohydrates/sweeteners, enzymes and beneficial bacteria recommended in the Under Current?
No. These tend to create bio-films and de-stabilize water chemistry.
Should I use Ca/Mg in the Under Current?
When using Reverse Osmosis (RO) or De-Ionized (DI) water Calcium Magnesium is recommended at 0.25-1mL per gallon. The Cultured Solution’s Coco Cal Supplement is your best choice.
Should I change my nutrient strength each week?
Follow manufacture’s nutrient schedule as recommended.
How frequently should I change my nutrients?
Change outs are recommended every 7 to 14 days, or if pH becomes de-stabilized (drifts more than 0.3 per day).
Do I need to flush my system between change-outs?
No, assuming only compatible inputs are being used a simple drain and refill is sufficient.
Is it possible to over-aerate my Under Current?
Yes, we recommend aeration levels stay between 0.75-1.5 liters per minute/per gallon. Exceeding these levels may cause mineral precipitation and nutrient de-stabilization.
Troubleshooting
What should I do if I make a mistake?
Observations and slight adjustments are the best way to dial your system in when in doubt give us or CCH2O a call.