how far away should lights be?

i have looked in the forum and have gotten a few different answers from reading. With 2 -75 watt florescent tubes, how far away should a seedling be, and how long until that amount of light is not enough?
With a 250W HPS, how far away from the tops of the plants? and if i were to grow with hps from day 1, would the stems be too weak (is using the 2 75 watt fluorescent a better idea for vegetation?)
i am using a soil medium. hps is 12/12 , florescent is 18/6
:rastasmoke:

Quote:

---

Originally Posted by natel628

i have looked in the forum and have gotten a few different answers from reading. With 2 -75 watt florescent tubes, how far away should a seedling be, and how long until that amount of light is not enough?
With a 250W HPS, how far away from the tops of the plants? and if i were to grow with hps from day 1, would the stems be too weak (is using the 2 75 watt fluorescent a better idea for vegetation?)
i am using a soil medium. hps is 12/12 , florescent is 18/6
:rastasmoke:

---

Use the CFL's for vegging. First 2 weeks are the most delicate. Try not to put the plants more than a few (3-5) inches for the first week. After that you can get them within the inch. And as long as it's not gonna burn the plant, the light can touch it! A fan blowing arcross the light usually helps to prevent burning.

The HPS will be too much for seedlings. Get as close as you can, as long as it's not "hot". Aside from the first 2 weeks of the seedlings life, general rule of thumb is that you cannot give too much light.

You say the HPS is 12/12, and Flourescent is 18/6? Do you have 2 seperate grow areas focusing on vegging and flowering? If you are starting from seed, ALL the lights must be on the same light schedule. 18/6 for vegging, 12/12 for flowering.

Quote:

---

Originally Posted by sum1cull911

Use the CFL's for vegging. First 2 weeks are the most delicate. Try not to put the plants more than a few (3-5) inches for the first week. After that you can get them within the inch. And as long as it's not gonna burn the plant, the light can touch it! A fan blowing arcross the light usually helps to prevent burning.

The HPS will be too much for seedlings. Get as close as you can, as long as it's not "hot". Aside from the first 2 weeks of the seedlings life, general rule of thumb is that you cannot give too much light.

You say the HPS is 12/12, and Flourescent is 18/6? Do you have 2 seperate grow areas focusing on vegging and flowering? If you are starting from seed, ALL the lights must be on the same light schedule. 18/6 for vegging, 12/12 for flowering.

---

Sorry, yes, two rooms. the 18/6 is one room for veg, 12/12 (hps) is in another for flowering. so 3-5 inches first 2 week.. when would be th earliest they could move to the 250w hps ?
i still have the covering over the cfl, what difference would it make if i were to change that?

When I say 3-5 inches, I mean from the day you plant the seed (not after it peaks its beautiful head). So you can move the cfls as close as you can get about a week after it's out.

If you want to move to HPS, you could do so about 1.5 week from it popping out of your medium. Start with the light farther rather than closer. I would say about a foot or so. Depending on how much heat your light gives off. Use your hand to gauge the heat. Then move it closer after each passing day, until you find the happy medium, where the plant isn't getting burnt.


I've grown from veg to flower, with all CFLS and Flourescent tubes. The HPS with probably speed up the plants growth.

alright. thank you!

Any suggestion for 56w T5 Grow bulbs? Thx

bump