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how far above plants should I put light?

Posted by kawaiineko_gardener 5a ( on
Wed, Mar 9, 11 at 19:27

I bought a 2 foot grow light. I'm using it in combination with a seedling flat and a heat mat. The instructions that come with using the grow light say place it 2"-4" above the seedlings.

When I called the seed catalog company I ordered the flat from (it's a miniature venting hobby greenhouse essentially) they said that using the grow light in combination with their miniature greenhouse, having the light 2"-4" above the plants/seedlings is too close, and will burn them.

They recommended placing the light 18"-24" above the seedlings. Will placing the grow light this far above the seedlings (and this is them being in the miniature greenhouse) cause them to be leggy or the recommended length of how far above to place them (the 18"-24") okay?

I don't want my plants to get burned by the light being too close, but I don't want them to be too leggy and spindly by placing it too far above them.

I'm just confused, cause I'm getting one recommendation from the seed company where I received the mini greenhouse from, but the instructions that came with the growlight say another thing.

Follow-Up Postings:

RE: how far above plants should I put light?

Sorry, but do you know where the SEARCH box in on this page? Did you ever think about using it? There are probably 10,000 posts related to how close to keep the lights.

But to answer your question: Whatever seed company you ordered the lights from are idiots. 2-4" is plenty - I've had seedlings touch the light (presuming they are fluro tubes, not MH or HPS!) and nothing bad happened, unless you call an earthquake, flood and volcano eruption bad.


RE: how far above plants should I put light?

I agree with Mike. Did I just say that again??

You need to learn how to use the search function.

Oh great I just lined her up for more questions.

You have asked the same questions over and over and over again and many of those questions had answers on the first page of the forum you posted on.
Read the top of every forum page until you can follow the directions without reading it.
Read the instructions at the bottom of every forum page until you can follow them without reading them.
Do a search, read the FAQ and go through the titles on every forum page before posting.
Many of the members are fed up and will probably ignore future questions especially if they know the answers are posted on the first page of topics. I've just been lurking on all of your topics and most of them are cross posted to other forums which goes against the TOS. I'm not falling for you naive questions when you too often ignore the answers you get. Do some research on your own and use the forum as it should be used or get reported.

RE: how far above plants should I put light?

hope you two feel better about yourselves now. Kawaiineko, there are plenty of gardening forums on the net where people are a little less mean, and you would be welcomed.

RE: how far above plants should I put light?

You should try searching the name kawaniineko_gardner and you'll see what I mean. She was welcomed with open arms until she started ignoring the answers given and asking the same question again and again on the same thread. It'll happen on other forums as well, once they get the same treatment.

RE: how far above plants should I put light?

I agree with Mike and Taz... I have helped this user many times on the 'starting from seed' forum.. no thank yous, no responses except for rude comments back. The SAME confusing questions have been asked since '09 with no thank yous or advice retained. I do not answer the posts anymore because he/she is rude and ignorant.


And if you want to start in with me being rude... check out my posts, I help and conversate with so many great people.. and I tried to help her/him.. not any more!1

RE: how far above plants should I put light?


Almost all of the regular visitors to GW are more than willing to provide advice - even if it our own version based on experience - to people asking for help. But it wrinkles my fur, and apparently others' when the OP justs seem to post to waste electrons, especially when the answer(s) have been posted dozens or hundreds of times.


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