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Starting seeds and how much light do they need

Posted by plantboy_grower (My Page) on
Sun, Jan 13, 08 at 23:00

Hi Everyone,

Once my seeds sprout, I'll need to get them under light. How much, that is the question...

I have a 4', 4 lamp T5 HO 54W flourescent New Wave fixture. I realize it is overkill to start my seedlings under this light, as it is more light than six little seedlings can use - however I can't think of another way to do it right now with any other lights I have in my house. I am hoping that in the future I will be able to start seedlings in corners of the system just as the last crop is about to be done.

Anyway, on with the question:

In order to save on power, could I start my seedling on 12 hours of light, even though people say to grow on 18 hours of light? Then once I actually transplant them into the hydro system they could be on 18 hours?

I am growing lettuce and basil.

Also do you feel there is enough growth difference to justify 18 hours vs. 12 hours for leafy crops like this?

Thanks in advance for any input!

Follow-Up Postings:

RE: Starting seeds and how much light do they need

Leave it on for 18 hours. The plant can only use so much light at once, it needs the time for metabolism.

RE: Starting seeds and how much light do they need

Look on attached link for what Cornell does with germination/seedlings.

Here is a link that might be useful: Cornell CEA

RE: Starting seeds and how much light do they need

My first hydro crop was lettuce. It bolted in 56 days. I called General Hydroponics (the makers of my Waterfarm) and they said the reason it bolted so early was that I was using too much fertilizer, and I should only have been using 12 hrs of light on lettuce. I assume that would be fine for the seedlings as well.

He sounded like he knew what he was talking about, but my new crop is very small, so I can't guarantee it.

Here is a link that might be useful: This may be interesting to you.

RE: Starting seeds and how much light do they need

Thanks to both of you - I'll keep those lights on for 18 hours.

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