RDWC feed chart
Feed rates and system care for recirculating deep water culture.
Read text version
Feed rates and system care for recirculating deep water culture (RDWC) on a standard 9-week flowering cycle. Grams of CropSalt powder per gallon of water.
Grams of powder per gallon of water
| Stage | Weeks | Per gallon of water |
|---|---|---|
| Veg + Early Flower | Veg and flower weeks 1–3 | Veg A 4.6 g + Veg B 3.1 g |
| Bloom | Flower weeks 4–7 | Bloom A 5.1 g + Bloom B 2.6 g |
| Cake | Flower weeks 8–9 | Cake 3 g |
Longer than 9 weeks
A 9-week cycle runs Cake for the final 2 weeks (weeks 8–9). On longer cycles, keep Bloom A+B going until the final 2.5 weeks, then switch to Cake alone at 3 g per gallon through harvest.
- 6.0Solution pH · Check pH and EC between swaps.
- 7 DAYSComplete nutrient swap · Drain and replace the full solution every 7 days.
- 0.2 mLBleach per gallon · When mixing and again 4 days later
Use bleach or another sterilizer
Use regular unscented bleach (6–8.25% sodium hypochlorite) at 0.2 mL per gallon, or another hydroponic sterilizer at its labeled rate. Add bleach when mixing and again four days later, based on the remaining solution volume.
Never mix concentrated bleach with RunClean — it can release chlorine gas. Add each to the reservoir separately.
Recommended pH doser
Use a Bluelab pH Controller Wi-Fi to automatically maintain pH 6.0. See the setup guide and our Garden sensors guide.
RunClean
Use 0.2–0.4 mL per gallon as a descaler. When using RunClean in place of pH Down, add it until you reach your target pH.