# Water pools on the surface and drains slowly: likely causes and fixes

> Water pools on the surface and drains slowly on cannabis is most often Overwatering (roots short of air) or Root-bound in a pot too small. How to tell them apart, the fix for each and what recovery looks like.

Also called: water sits on top, soil compacted, slow draining pot, puddles on soil.

Run the checker with this sign: https://genetixbay.com/knowledge/diagnose/?at=roots&s=water-pools-slow-drain

## 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)

### Root-bound in a pot too small (Less likely)

- Kind: Root zone; urgency: Deal with it this week
- Fix: Up-pot photoperiods into a container about 2-3x larger, loosening circling roots gently. Autoflowers: don't transplant; increase watering and feeding frequency instead. Small pots can still grow big plants with high-frequency fertigation (several feeds a day).
- Recovery: New white roots in the fresh medium within 5-7 days; daily wilting stops.
- 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: 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: [Cannabis root problems: the master decision tree](https://genetixbay.com/knowledge/diagnosis/root-problems-decision-tree.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.