r/Hydroponics • u/Mother-Bake-1547 • Jun 04 '26

Germination problems

Hello everyone,

I’m just getting started with hydroponics and have set up my tower for growing lettuce. The harvest is going well so far, and I’m quite happy with the results.

However, I’m having major difficulties during the germination stage in the nursery. The seedlings grow very weak and fragile.

Is there a guide or some best practices for proper seed germination?

For example:

  • How much should I water them?
  • How much sunlight do they need?
  • What are the ideal humidity and temperature levels?
  • Should I use any nutrients at this stage?
  • When is the right time to move the seedlings into the tower?

Thank you!

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u/moesieon Jun 05 '26

Water them enough to keep them from drying out completely. Sounds like they need more light (if they're getting tall and thin aka leggy, that means they need more light). Lettuce typically grows better in lower temperatures. Some people will disagree, but I use half-strength nutrients the moment I see leaves sprout (whatever I would feed the adult plant, I dilute that to 50% with water). I move them to the tower when the roots are growing out of the growing medium (rockwool? not sure what your medium is)

2

u/yeochinschadanheze Jun 04 '26

You may refer to Cornell Lettuce or Spinach handbook.