how many lumens is enough?

D

doingfine

Well-Known Member
im ready for growing stage , can anyone tell me im growing 3 plants 18 inches high is too many lumens too much? is their a limit? how far should i keep these lights to the plants? im using 400 watt high pressure sodiums for the tops and was gonna use some t12s on the sides while i rotate the plants?
any help would be great
 
K

kevb123

Well-Known Member
400 will be fine but 600 or 1000w would b better.
keep the light 6 ft above cuttings/seedlings and gradually lower it over a week to 2ft above cannopy.
 
W

Wetdog

Well-Known Member
General rule of thumb:
3000 lumens/sqft for vegging
5000 lumens/sqft for flower

While I think 6' is a bit high, do start well above and gradually lower the lights to just high enough to where they don't burn.

I don't think the T-12's will be of much benefit. Not if the plants are only 18".

Wet
 
Serapis

Serapis

Well-Known Member
If you have T12's ALREADY, use them as side lighting as you planned. However, if you are going shopping, get at least T-8's. Wal*mart sells 4' T-8 lights and bulbs for under $10 each... I would not use 1000w on 3 plants. that is just overkill and will prsent new problems, such as getting rid of the heat generated. I've also never read or advised anyone to keep a light 6' from a plant top..... what's the guy got? 10' ceilings?
 
K

kevb123

Well-Known Member
Serapis said:
If you have T12's ALREADY, use them as side lighting as you planned. However, if you are going shopping, get at least T-8's. Wal*mart sells 4' T-8 lights and bulbs for under $10 each... I would not use 1000w on 3 plants. that is just overkill and will prsent new problems, such as getting rid of the heat generated. I've also never read or advised anyone to keep a light 6' from a plant top..... what's the guy got? 10' ceilings?
Click to expand...
6ft above cuttings or seedlings it said as you will burn them to death otherwise.
 
D

doingfine

Well-Known Member
do t8's produce more lumens?
and how do you know if your burning the plants?
so i would assume that 2 400 watt sodium is fine with the t8's for what i have?
thanks guys for all your help
 
Magnificient

Magnificient

Well-Known Member
doingfine said:
do t8's produce more lumens?
and how do you know if your burning the plants?
so i would assume that 2 400 watt sodium is fine with the t8's for what i have?
thanks guys for all your help
Click to expand...
The only real difference between t5, t8, and t12 lights is the diameter of the bulb. The t5s are 5/8", t8s are 1", and t12s are 1 1/2". The t5s are better for growing because they put out more lumens per square inch.
 
You must log in or register to reply here.
Top