Deep water culture is one of the fastest ways to grow cannabis indoors — roots sit directly in an oxygenated nutrient solution with nothing slowing them down, which means faster vegetative growth than soil or coco. It's also less forgiving: your reservoir is the entire root zone, so mistakes show up quickly.
"DWC rewards attention and punishes neglect faster than any other method. Check your reservoir daily — it's not optional." — Andrew Woodward
The basics
- Net pots suspend the plant just above the waterline, with roots growing down into the reservoir below.
- An air stone keeps the solution oxygenated continuously — this is the single most important piece of equipment in a DWC system. Roots sitting in stagnant, low-oxygen water is the fastest route to root rot.
- The reservoir is the whole root zone, so temperature, EC, and pH swings hit the plant immediately, with no buffering medium to soften them.
EC and pH for cannabis in DWC
| Stage | EC (mS/cm) | pH |
|---|---|---|
| Seedling / clone | 0.4–0.8 | 5.8–6.0 |
| Early vegetative | 0.8–1.4 | 5.8–6.0 |
| Late vegetative | 1.4–1.8 | 5.8–6.0 |
| Early flower | 1.6–2.2 | 5.8–6.2 |
| Peak flower | 1.8–2.6 | 5.8–6.2 |
| Late flower / flush | Taper down to 0.2–0.4 | 5.8–6.0 |
Keeping the reservoir healthy
- Keep reservoir temperature between 65–72°F. Warmer water holds less dissolved oxygen and is far more hospitable to root pathogens.
- Top off with plain pH-adjusted water between full changes — plants drink water faster than they drink nutrients, so letting EC creep up unchecked between changes is a common mistake.
- Do a full reservoir change every 7–14 days even if your numbers still look fine, since nutrient ratios drift as the plant selectively uptakes different elements.
- Watch for root color. Healthy DWC roots are white to cream-colored. Brown, slimy, or foul-smelling roots mean it's time to check oxygenation and reservoir temperature immediately.
The bottom line
DWC's speed comes from direct root-to-solution contact — which is exactly why oxygenation, temperature, and consistency matter more here than in any other growing method. Get those three right and DWC is one of the most productive ways to grow.
Our DWC Germinator kit gets a reservoir set up correctly from day one, and the Aero-Gro Pro 5-in-1 Water Meter keeps you on top of EC, pH, and temperature in one check.
Tools for Serious Growers
Everything mentioned in this article — and more — available in the Aero-Gro store.