150w hps vs. 250w hps

[jose m]

hi all!

 

i'm starting my first indoor grow in a 60x60x120 (0.36m2) grow box. i did all the construction work and it's ready to go but i'm having trouble deciding whether to use a 150 or 250w hps. i will use fluoros for earlier stages of vegetation and then switch to hps later. i want to have 2 (or three if possible) plants in the box, and will probably be using lst method. the 150w has 17000 lumens and the 250w 31000 lumens. i was advised to use the 250, but it seems too much to me. is it, or should i go with the 250? is there such a thing as too much light?

thanks,

 

jose

[Gazza2001au]

you can use either one in that size box i'd personally prefer the 150w it'll be less heat and still give you 37.5watts per square foot but the 250w will give better growth in the corners but the heat will be a problem unless u live in a cooler area

[jose m]

you can use either one in that size box i'd personally prefer the 150w it'll be less heat and still give you 37.5watts per square foot but the 250w will give better growth in the corners but the heat will be a problem unless u live in a cooler area

 

yeah, the heat issue is the main reason i can't decide... the box is under a window so some cooling comes from there, but the room it's in is overall rather warm. i think i will use the 150 hps and add an 80 w fluoro with an output of 6000 lumens which doesn't produce a lot of heat. this combination seems very decent to me... any comments?

[Gazza2001au]

go for it start a grow diary

[Pam]

Sounds good! Adding the CFL to my flower box made a big difference.

[WantDaChronic]

i'd go the 150w hps with a few fluros in there too...less heat, more light, better spectrum = bigger buds

[jose m]

yep, i'll do just that... thank you all for replying. can't wait to see it spurt

[Al B. Fuct]

Mixing fluoros and HPS is fraught with complications, mainly due to the lamp-to-leaf spacing requirements. Fluoros must be within a couple of inches of foliage where HPS must be 1-3 feet away depending on lamp size.

 

Fluoros are low-intensity lights and half as efficient as HPS. Fluoros are fine for clones and vegging small plants but don't do well for flowering due to the low intensity.

 

The commonly accepted rule-o-thumb for HPS lighting is 50W/sq ft of lighted space. This will produce good bud density and weight. If your floor is 60cm x 60cm (about 2' x 2'), you're lighting about 4 sq ft. Per the 50W/sf guideline, you need about 200W; I'd opt for the 250HPS.

 

There's a lengthy discussion of CFLs v. HPS here.

[Pam]

Evidently my plants haven't heard about all that Al....

 

I don't know what type of CFLs you've been looking at but I have to tell you a 120w flood can light up my entire yard better than any other type of lamp. And the same lamp inside the box is really very bright, but... the addition of the CFL to the HPS isn't really to add more light but to add some blue spectrum, and to light up from under the plants.

 

The girls like it, and whatever the girls want they get, in my book, scientifically sound or not.