[Jamaican876]

Hey guys I'm deciding between a 600 watt hps and a 400 watt hps for a 5x4 space.my question is would a 400 watt give me rock hard buds considering I maintain a decent environment for the girls?

[Granger2]

In a 5x4 it would take a 1000w to get intense enough light to get rock hard buds. 5x4 = 20 sq ft. You need a minimum of 50w per sq ft. -granger

[GanjaGuru710]

Just food for thought, dense flowers come from a culmination of things. Proper wattage, feeding schedule/recipe and room temperatures are very important when it comes to nug structure. Even genetics can play a small role. I must say i've seen a lot growers struggle with loose arid buds simply because they didn't ventilate the heat in their garden enough.

[nameless]

4 and 600s will give you dense rock hard buds if your environment is right. make sure there is enough airflow and or cooling to have proper space between light and plants. if your using the entire 5 x 4 as a flowering area id go with an aircooled 1k hps or maybe 2x 315 cmh

[Floridian]

I have found the 50 watts sq ft rule to be totally important in maximizing your yield.When I added a third 1K HPS in my 8 by 8 flower room things really began to rock.That and using R/O water were game changers in my grows.Of course you have to keep adequate temps one way or another

[Joint Lock]

Average grower will see about 5-8 oz dry from 400w
from a 600w about 10-16 oz dry (great for 3 x 3 space)
from 1000w 1-2lb dry or more (Great for 5 x 5)


half a gram per watt rule above


Nug density isn't even worth playing with a 400w in my opinion . Myself I only rock 600w's as they give out double the light of a 400w if u look at outputs . 400w -50,000k lumens 600w 95,000 lumens . A digital ballast will allow u to get the same power as a 400w but only using 300w when dimmed down. 600w is most efficient and what I would use maybe 2 of em for that space . digital ballast that can be dimmed . that way u can control your grow 300w -1200w with 2x 600w and help control the heat ect as needed .


Floridian: 50w per ft rule is dead in the water . 50w from a 400w = 6240 lumens
50w from a 600w = 7500 lumens
50w from a 1000w = 8000 lumens


The numbers vary so u could say u would want 6000-8000 lumens per ft I suppose but the numbers all different . Not busting your chops . Just showing how that's a bad example due to 2000 lumen difference . I know were after PAR anyway . Just making a point was all

[Easy7]

Lack of penetration is also a thought with lower wattage. A 400w is a 3' x 3' tent, sog or scrog.

[Granger2]

Watts / sq. ft. = watts per sq ft.

[Tonygreen]

Genetics and heat are two big factors besides light. Sour Bubble will make thunkers in shaded light even, grinspoon wont ha.
When it gets hot them buds want to open up and grow apart more so they can breathe and sweat.

[Floridian]

I don't know why you think 50 watts a sq foot is dead in the water Joint lock.Im glad I didn't think that way when I set myself up.Par watts not lumens are what you need to consider anyway.The par watts from hortilux or other quality horticultural lamp is what to look at when flowering.You can get plenty of lumens from an HPS designed to light up an underground parking area