# Medium stays wet for 4+ days after watering: likely causes and fixes

> Medium stays wet for 4+ days after watering on cannabis is most often Overwatering (roots short of air), Humidity too high / VPD too low or Cold root zone (below about 16 °C / 61 °F). How to tell them apart, the fix for each and what recovery looks like.

Also called: soil never dries, pot always wet, soil stays soggy, coco not drying.

Run the checker with this sign: https://genetixbay.com/knowledge/diagnose/?at=roots&s=medium-stays-wet

## Likely causes, most likely first

### Overwatering (roots short of air) (Likely)

- Kind: Root zone; urgency: Deal with it this week
- Fix: Water only when the pot is clearly lighter (about half the water used), then water to 10-20% runoff. Seedlings in big pots: water a small ring near the stem only. Add air: fabric pots, 25-40% perlite, no saucer standing water. Let a soaked pot dry back before the next watering.
- Recovery: Leaves lift within a day of drying back; colour and growth recover within 5-7 days.
- Confirm: Lift the pot and check moisture at depth: Lift the pot right after a full watering to learn its wet weight, then lift before each watering. Water when it is clearly lighter (about half the added water gone). Push a finger or a moisture probe 5 cm (2 in) down. Heavy for 3-4+ days with droop: overwatering. Very light with limp papery leaves: thirst.
- Confirm: Look at the roots: Hydro: lift the net pot and look at the root mass in good white light. Containers: tip the plant out with a hand over the medium and look at the edges and bottom of the root ball. Healthy roots are white to cream with fine fuzzy tips. Brown roots whose outer layer slides off between the fingers leave a bare thread: rot. Firm, evenly tan roots with white tips in coloured solution are staining.
- Confirm: Smell test of roots, medium and reservoir: Smell the roots, the bottom of the root ball, the drain water or the reservoir up close. Healthy roots smell earthy or of nothing. A sour, rotten, swampy or sewage smell means anaerobic conditions and rot. In hydro, a slimy feel on the reservoir walls or tubing adds to the case.
- Article: [Drooping cannabis: overwatering vs underwatering](https://genetixbay.com/knowledge/diagnosis/drooping-overwatering-vs-underwatering.md)

### Humidity too high / VPD too low (Possible)

- Kind: Environment; urgency: Act within a day or two
- Fix: Target about 55-70% RH in veg, 50-60% early flower, 40-50% late flower (leaf VPD 1.0-1.5 kPa in flower). Dehumidify, raise exhaust, keep air moving under the canopy and watch the lights-off spike (dew point). High RH in flower raised bud-rot risk and in one study delayed flowering and lowered cannabinoids.
- Recovery: RH holds in band through lights-off for 3+ days; no new mould signs.
- Confirm: Check temperature and RH at canopy height with a calibrated sensor: Put a calibrated sensor (salt test: a sealed bag with damp table salt reads 75% RH after 8-12 hours) at canopy height, out of direct light, and log for 24 hours including lights-off. Look for lights-off RH spikes and dew point.
- Article: [Humidity by stage: RH targets from clone to cure](https://genetixbay.com/knowledge/environment/humidity-by-stage.md)

### Cold root zone (below about 16 °C / 61 °F) (Less likely)

- Kind: Root zone; urgency: Deal with it this week
- Fix: Raise root-zone temperature to 18-22 °C (64-72 °F): lift pots off cold floors onto insulation, warm the room at night, use an aquarium heater in reservoirs (with a thermostat), water with room-temperature solution.
- Recovery: Growth resumes and new leaves green within a week.
- Confirm: Measure reservoir and root-zone temperature at the end of the light period: Measure the solution in the reservoir and in the root chamber or bucket, at the warmest time of day. Target 18-22 °C (64-72 °F). Above about 23-24 °C (73-75 °F), dissolved oxygen falls and Pythium risk rises; below 16 °C (61 °F) uptake slows.
- Confirm: Lift the pot and check moisture at depth: Lift the pot right after a full watering to learn its wet weight, then lift before each watering. Water when it is clearly lighter (about half the added water gone). Push a finger or a moisture probe 5 cm (2 in) down. Heavy for 3-4+ days with droop: overwatering. Very light with limp papery leaves: thirst.
- Article: [Temperature by stage: day, night and root-zone targets](https://genetixbay.com/knowledge/environment/temperature-by-stage.md)

## Note

Guidance, not a guarantee. The checker weighs common causes against what you tell it; confirm with the tests before you treat, change one thing at a time and watch the new growth.