# RDWC

> RDWC (recirculating deep water culture) links several aerated buckets to a central control reservoir, pumping solution through all of them to keep conditions uniform.

- Canonical: https://genetixbay.com/knowledge/glossary/rdwc.html
- Also written: recirculating deep water culture, recirculating DWC, re-circulating DWC, under current, undercurrent
- Glossary category: Systems and media · Evidence: Grower practice
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Recirculating deep water culture is a hydroponic system in which several [DWC](https://genetixbay.com/knowledge/glossary/dwc.md) sites are connected by pipes to a control bucket or reservoir, and a pump moves solution continuously through the whole loop. Each site is aerated, and adjustments to [pH](https://genetixbay.com/knowledge/glossary/ph.md), [EC](https://genetixbay.com/knowledge/glossary/ec.md) and temperature are made in the control bucket only.

## In practice

The larger shared volume is more stable than single buckets, and one [chiller](https://genetixbay.com/knowledge/glossary/chiller.md) can cool the whole system. Growers typically size the pump to turn over the full system volume several times per hour. Keep the control bucket accessible, insulate and lightproof all buckets and lines to stop algae and heat gain, and keep the solution around 18-21 °C (64-70 °F).

The trade-off is shared risk: a [root disease](https://genetixbay.com/knowledge/glossary/root-rot.md) or pump failure affects every plant at once. Most growers run either a [beneficial-microbe reservoir](https://genetixbay.com/knowledge/glossary/beneficial-microbe-reservoir.md) or a fully sterile one.

## Don't confuse with

- **DWC**: one standalone bucket.
- **Ebb and flow**: also recirculates, but floods and [drains](https://genetixbay.com/knowledge/glossary/runoff.md) a tray instead of holding roots in solution.

## Related terms

[DWC](https://genetixbay.com/knowledge/glossary/dwc.md), [Reservoir](https://genetixbay.com/knowledge/glossary/reservoir.md), [Chiller](https://genetixbay.com/knowledge/glossary/chiller.md), [Dissolved oxygen](https://genetixbay.com/knowledge/glossary/dissolved-oxygen.md), [Recirculating system](https://genetixbay.com/knowledge/glossary/recirculating-system.md)

## Read more

- [Recirculating deep water culture (RDWC)](https://genetixbay.com/knowledge/systems/rdwc.md)

## Sources

1. Resh HM, 2022. Hydroponic Food Production, 8th ed. CRC Press. https://doi.org/10.1201/9781003133254
2. Colorado State University Extension PlantTalk 2043. Root disease problems and management in hydroponic systems. https://planttalk.colostate.edu/topics/miscellaneous/2043-root-disease-problems-management-hydroponic-systems/