lots of 400w hps questions!

mammal

mammal

Well-Known Member
for my second grow im growing 6 plants under a 400w hps (upgrading from cfls) in a 1mx1mx1.8m growtent. being new to this HPS lark i have a few questions that i hope yall could answer!

1) at what stage can i start using the 400w? i'll be germinating under the cfl's from the first grow but i want to use the good lamp as soon as possible. can i use the single bulb for the whole veg/flower cycle? (i intend on 1month veg)

2) will it really give off much more heat than the cfls? i had no problem with temps in my last grow, the room is pretty well naturally ventilated, and the fact winter will be soon apon us will make it even easier. i really cant sink much more money into this grow for ventilation etc, but if i really need to what kinda fans will i need?

thanks for any help, and any other tips you could give me will be greatfully recieved, thanks :D
 
After you get a lil growth on the seedlings straight to hps if you want.
1 bulb? Cfl?

Yes the 400w will give off alot more heat. Do you have any kind of ventilation for the Tent?
If not you will need something.
a duct booster will help if you strapped.
 
im going to leave the bottom couple of foot of the front door of the tent open with an occilating fan blowing air in, but theres nowhere for the air to escape apart from the short opening at the top.

looks like i'll have to invest in a fan :(
 
mammal said:
for my second grow im growing 6 plants under a 400w hps (upgrading from cfls) in a 1mx1mx1.8m growtent. being new to this HPS lark i have a few questions that i hope yall could answer!

1) at what stage can i start using the 400w? i'll be germinating under the cfl's from the first grow but i want to use the good lamp as soon as possible. can i use the single bulb for the whole veg/flower cycle? (i intend on 1month veg)

2) will it really give off much more heat than the cfls? i had no problem with temps in my last grow, the room is pretty well naturally ventilated, and the fact winter will be soon apon us will make it even easier. i really cant sink much more money into this grow for ventilation etc, but if i really need to what kinda fans will i need?

thanks for any help, and any other tips you could give me will be greatfully recieved, thanks :D
Click to expand...

what about the bulb i have the same 400w hps will i need a new light for the flowering 12/12
 
More heat depends on if you were burning over 400w of cfl's before. If you were, the heat is comparable.

Put the ballast outside the tent also.
 
unfortunately the ballast is part of the lamp so thats not an option. the room is light tight so i think i'll just leave the front of the tent open.
 
mammal said:
for my second grow im growing 6 plants under a 400w hps (upgrading from cfls) in a 1mx1mx1.8m growtent. being new to this HPS lark i have a few questions that i hope yall could answer!

1) at what stage can i start using the 400w? i'll be germinating under the cfl's from the first grow but i want to use the good lamp as soon as possible. can i use the single bulb for the whole veg/flower cycle? (i intend on 1month veg)

2) will it really give off much more heat than the cfls? i had no problem with temps in my last grow, the room is pretty well naturally ventilated, and the fact winter will be soon apon us will make it even easier. i really cant sink much more money into this grow for ventilation etc, but if i really need to what kinda fans will i need?

thanks for any help, and any other tips you could give me will be greatfully recieved, thanks :D
Click to expand...


1) you can use the new HPS to grow and flower the plant once out of seedling stage read: 4 nodes of growth or more. HPS provides plenty of Lumens for good vegetative growth and the red color gives better foliage penetration for vigorous flowering.

2) If you had 400 watts of CFL in there before, the HPS will give off less heat overall, but I am assuming you did not have that much CFL in there, so yes you will see an increase in heat, a good fan blowing across the lamp will cure that.
 
smppro said:
CFLS in my room 80degrees HPS in my room 95 degrees
Click to expand...
how many actual watts of CFL do you have there?
No doubt ten 16 watt bulbs will give off less than a 400 w hps, but 24 of them would put out more heat and have less overall lumens also. CFL is just not as efficient as HPS.
 
12 42 watt, less lumens, and more watts than hps, but i can manage the temps, so im giving them a go
 
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