Light height question - Indoor Grows - Hydro - International Cannagraphic Magazine Forums

05-18-2004, 01:27 AM

I have a 430w Son Agro for flower and a 400MH for veg. I'm in flowering now. I've kept the light between 18" and 24". Good or bad? What would be right the right height? Veg and flower the same?

Captain Canibus · 05-18-2004, 02:36 AM

Keep it as close as possible. I got the same lite for veg. Stick your hand under the lite and see how close you can get before it feels hot. Usually about 12". It will reduce the stretch.

05-18-2004, 03:46 AM

Thanks Capt. well now I know why she stretched so much. I'll move the light down when it comes on again in the morning. Do you think I've lost any bud development with the light being maybe an extra foot away?

05-18-2004, 03:57 AM

What kinda hood?

Cooltube or vented hood with inclosed glass?

I could get my 600w Hortilux within about 8" to 10". I was pulling 440 cfm through a 6" cooltube. No burning nothing but I was movin some air.

I use the back of my hand as an indicator. If it's warm there , it's warm on the plants. like checkin babies milk.

Tex

05-18-2004, 04:02 AM

It's a vented hood Tex. I have an exhaust fan pulling from the top vent. I have the glass but took it off because someone at the hydro shop said I'd get better results with out it. I believe it's called a super grow wing reflector, made by hydrofarm.

05-18-2004, 04:13 AM

I looked aat one and couldn't tell, is there a 4" flange mount on it that you have your suction hooked to?

The guy is right about the glass, it does cut the effeciency down alot.

how much suction on it?

Tex

05-18-2004, 04:16 AM

Yes Tex I have a four inch flange mounted with ducting taking it out of the room to were the fan is mounted.

buddyJesus · 05-28-2004, 10:07 PM

the loss of efficiency is about 10 percent with regular glass. There is a special glass that has a loss of only 5 percent that I saw at a web site but I believe they only sell it as tubes.

with my 600w bulb and glass, I can get a foot closer to the plants. using the formula in cervantes book that halvens the distance and the light is four times as intense. I believe that more than makes up for the 5-10% lumen loss from using the glass. If you don't want to use glass you can get closer to the canopy by using a light mover. The light is moved away before the heat builds up too high.

I hope I didn't make you think too hard!

05-18-2004, 01:27 AM	#1
Guest Guest Posts: n/a	Light height question I have a 430w Son Agro for flower and a 400MH for veg. I'm in flowering now. I've kept the light between 18" and 24". Good or bad? What would be right the right height? Veg and flower the same?
	Quote

05-18-2004, 02:36 AM	#2
Captain Canibus Member Join Date: Jan 2004 Location: US-Midwest Posts: 318	Keep it as close as possible. I got the same lite for veg. Stick your hand under the lite and see how close you can get before it feels hot. Usually about 12". It will reduce the stretch. __________________ The man who says it can't be done shouldn't interfer with the one who is doing it. To be the best YOU can be, You are only competing with yourself.
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05-18-2004, 03:46 AM	#3
Guest Guest Posts: n/a	Thanks Capt. well now I know why she stretched so much. I'll move the light down when it comes on again in the morning. Do you think I've lost any bud development with the light being maybe an extra foot away?
	Quote

05-18-2004, 03:57 AM	#4
Guest Guest Posts: n/a	What kinda hood? Cooltube or vented hood with inclosed glass? I could get my 600w Hortilux within about 8" to 10". I was pulling 440 cfm through a 6" cooltube. No burning nothing but I was movin some air. I use the back of my hand as an indicator. If it's warm there , it's warm on the plants. like checkin babies milk. Tex
	Quote

05-18-2004, 04:02 AM	#5
Guest Guest Posts: n/a	It's a vented hood Tex. I have an exhaust fan pulling from the top vent. I have the glass but took it off because someone at the hydro shop said I'd get better results with out it. I believe it's called a super grow wing reflector, made by hydrofarm.
	Quote

05-18-2004, 04:13 AM	#6
Guest Guest Posts: n/a	I looked aat one and couldn't tell, is there a 4" flange mount on it that you have your suction hooked to? The guy is right about the glass, it does cut the effeciency down alot. how much suction on it? Tex
	Quote

05-18-2004, 04:16 AM	#7
Guest Guest Posts: n/a	Yes Tex I have a four inch flange mounted with ducting taking it out of the room to were the fan is mounted.
	Quote

05-28-2004, 10:07 PM	#8
buddyJesus Member Join Date: Apr 2004 Location: Colorado/Michigan Posts: 40	the loss of efficiency is about 10 percent with regular glass. There is a special glass that has a loss of only 5 percent that I saw at a web site but I believe they only sell it as tubes. with my 600w bulb and glass, I can get a foot closer to the plants. using the formula in cervantes book that halvens the distance and the light is four times as intense. I believe that more than makes up for the 5-10% lumen loss from using the glass. If you don't want to use glass you can get closer to the canopy by using a light mover. The light is moved away before the heat builds up too high. I hope I didn't make you think too hard!
	Quote