Moist is not waterlogged — roots need air as much as water

Seeds and roots breathe. A tray that never dries at the bottom starves them of oxygen, then invites damping-off and gnats. NFT and DWC fail the same way when solution sits stale or pumps pause. Small cells swing from bone-dry to swamp in an afternoon — that is why weight and feel beat a calendar.

Water early enough that foliage dries. Do not leave trays in a stagnant puddle. Bottom-water when it keeps leaves dry, then dump the reservoir. In heat, more often with less each time usually beats one heroic flood.

If roots are brown and the surface still shines, you watered a swamp.

In this series

• Design the house for the climate that will kill the crop
• Ventilation is life support — trapped sun kills faster than a dry bed
• Prove water, drainage, and backup before you buy a timer
• Moist is not waterlogged — roots need air as much as water
• Space, screens, and a twice-weekly walk beat a late bottle
• Plan backward from harvest; a full green house is not a result