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Grow Lights with Humidity Domes

Posted by mikep_cfl z9b FL (My Page) on
Thu, Dec 27, 12 at 0:53

Hello everyone -
I'm preparing to start some flower bulb seeds (hippeastrum a/k/a Amaryllis) and this year I thought I would try using grow lights and heat mats. I've decided on a "starter" setup that comes with T5s, 6500K, 1020 flats, 7 inch humidity domes and the heat mats. I bought a thermostat. Also, I have some standard size domes on hand.

I've been reading various threads in this forum for advice and it doesn't seem like many people use grow lights and humidity domes at the same time. Most of the advice I've received about starting these seeds says to use humidity domes (or plastic) to keep the humidity high.

I'm going to use the standard height domes until the seeds germinate and get a few inches tall and then shift to the taller 7 inch domes.

I understand the T5s can get hot and I'm concerned about melting the domes. Is this a real concern? Where should I position the lights above the domes; the standard 3"-4"? Does this setup sound like I'm on the right track?

Any advice will be appreciated.

Mike/Central Florida

Follow-Up Postings:

RE: Grow Lights with Humidity Domes

Humidity domes are for germination only. Same goes for the heat mats - germination only. Once the seeds have germinated the domes need to be removed and the seedlings are removed from the heat mats and placed under the lights. Failing to do so leads to root rot, leggy growth, damp-off and other fungus issues.

So to answer your question, once the seeds have germinated on the heat mats, remove the dome or at least prop them well open and turn off the heat mats.



RE: Grow Lights with Humidity Domes

Thanks Dave -
Heat mats removed after germination. Got that part. And I'll take care to use taller (7") humidity domes which are ventilated right after germination.

I would remove the domes as well, however, I know from experience seedlings of this plant variety like high humidity, generally for the first year. Many growers float the seeds to germinate them, then transplant to their favorite medium. I lose too many in the transplanting.

My real concern was whether grow lights are used with heat mats and humidity domes at the same time (until germination) and if there is a danger of the grow lights melting the plastic domes. I'm guesing not at this point - maybe I'm being a little too cautious.

Thanks again

RE: Grow Lights with Humidity Domes

Using the lights with the domes and mats is only necessary when the seed variety requires light to germinate. A few flowers do but none of the average vegetables require light for germination. Otherwise the lights aren't on until after germination.

Some use the lights as an additional source of heat if their area is especially cool but when used that way they don't need to be all that close.


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