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Lower wattage in flower ok?

Bagseed68

New member
Hi,
I currently have several plants of different ages vegging under the same 1000w mh. When I move a select few to the flower room is it OK to drop down to 400w hps? A friend told me I should've done it the other way around; 400w mh in veg 400+ hps in flower. Is this true?
 

GOT_BUD?

Weed is a gateway to gardening
ICMag Donor
Veteran
The "golden standard" for years was 50 watts of light per square foot for flowering. I'm not sure if that's changed recently (so many new discoveries about our beloved plant I've stopped trying to keep up), but it's a good rule of thumb.
 

MJPassion

Observer
ICMag Donor
Veteran
Yes...


You certainly moved the wrong way.
Your friend is correct as is the above comment.
 

Douglas.Curtis

Autistic Diplomat in Training
It's ok. Your biggest issue will be undergrowth which the 600 lit up, and the 400 now doesn't. The plant will flower without issues and your yield should be unchanged for a 400w.

I veg and flower under 50-55w per square foot. So, whether it's the 400w or the 600w or 1000w, the plants are getting the same intensity. :) It builds stout plants which flower out well.

Yes, a 400w light is a great veg light for plants you'll be flowering under a 600w or a 1000w. :)
 

Switcher56

Comfortably numb!
I'm running a 300W in veg and a 600W in bloom. (2x2x3, 3x3x6). At the high end (50) = +100 & 60W respectively. A 750 would have been better (+210) but at this point I am happy with my set up. I grew the seedlings with CFLs and didn't like the result. Too leggy! My Bonsai mums were struck under the 300 and it provided a far better result. Later... I may add another 600 to the flower room or an 800W. I will have to look at the ppfd foot prints for coverage to assist my decision. (heat)
 

Bagseed68

New member
I appreciate your responses. Perhaps I should have mentioned that the veg room is7×8×8 and the 1000w mh is about 30" above the canopy. The bloom area is a 3×3×6 tent and the 400w hps will be approximately 14" above. I realize that this is slightly below the standard 50wpsqf but if I bump up to 600w I'll have to move the lighter further from the canopy as well as contend with excess heat issues. Should I still go for it?
 

Douglas.Curtis

Autistic Diplomat in Training
Unless you have multiple 400w flowering areas, you would do better to switch your veg to the 400w and flower under the 1000w. With a 7x8x8, you have enough space for 2 1k lights.


600w is too much light for my liking in a 3x3.
 

Snook

Still Learning
Veteran
would it be possible to move the 1K into the bloom area and the 400w into the veg area? The bloom area should be bigger than the veg area, if they handle 1K in veg, they'd be as happy in bloom.
 

CaptainDankness

Well-known member
I appreciate your responses. Perhaps I should have mentioned that the veg room is7×8×8 and the 1000w mh is about 30" above the canopy. The bloom area is a 3×3×6 tent and the 400w hps will be approximately 14" above. I realize that this is slightly below the standard 50wpsqf but if I bump up to 600w I'll have to move the lighter further from the canopy as well as contend with excess heat issues. Should I still go for it?

Yeah, the flower room should definitely be the bigger room. You can never keep up with a perpetual grow.

7x8 is pretty big as well you'd really want like 4 600w hps's. Of course 3x3 is a little small for a veg room for 4 600w lights.
 

Switcher56

Comfortably numb!
Unless you have multiple 400w flowering areas, you would do better to switch your veg to the 400w and flower under the 1000w. With a 7x8x8, you have enough space for 2 1k lights.


600w is too much light for my liking in a 3x3.
Depends if they are LED or not. I went with LED for a couple of reasons: a. size of grow; b. heat; and power consumption. :tiphat:
 

Raho

Active member
Veteran
The only reason to drop light intensity is if you can't manage the heat they generate. Otherwise, the goal of indoor growing under HID is to try and reproduce the intensity of the sun.
50 watts/sq ft is the generally accepted compromise number understanding that the cost of cooling "the sun" in your room is too high to be practical.

Another consideration include headroom. If you don't have enough room to keep the lights away from your canopy, you can burn your plants with (almost) any grow light.
 

pinkus

Well-known member
Veteran
Long story short; yes, your system is basically inverted.

Swap vegetative room for flowering room.
 
Go for it. as long as you only place 3 to 4 plants in flower under the 400. 3 weeks after flip, decide if you need to trim the undergrowth in the shadows. Just guessing without pictures.
I don't agree with vegging under 1000 watts, not with your flower room limitations. But I don't pay your electric bill.
 

Bagseed68

New member
Great feedback! Thanks! The reason my bloom tent is smaller than my Veg is because this is a 2nd bloom room. The veg room has a couple dozen plants, all in various stages of growth. Only a select few will go into this a smaller Bloom room. Heat and ability to move the light closer to the canopy was the main reason I went with a smaller wattage lamp. I would love to swap out the 1000w for the 400, however my 1000 is mh, not hps.
 
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