Prove water, drainage, and backup before you buy a timer

Hydroponics and drip make a greenhouse look modern. They still need a source that can fill the day, emitters that actually wet the root, and a drain that leaves. Standing water grows gnats and root death. Sodium-softened water and an untested well write salt into every cycle. Catch-test a zone instead of trusting the controller clock.

Backup is a person and a can, or a gravity tank, not a second app. Holiday and power-cut watering must be written. Zones should match crop thirst, not the number of spare solenoid valves you were sold.

If plants dry at the far end while the header looks full, fix delivery and drain before you add another pump.

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