400w or 600w

i was wondering if anyone could give me thier opinion. The 400w i wanted is out of stock at the moment (good price!). But the 600 is a little bit more and i am keen to get started, this will be my first grow in an attic - as i live in the northern hemisphere i plan to grow enough year round so that i can give summer a miss because of temperature control. Anyway the question is how much hotter is the 600 than the 400 the space will be about 4 1/2' *3*3 (growing for personal only) ? thanks

the 600w is not much hotter. the 600w is an all around good light

i agree with g13, the 600w is a better investment and you will get better grows with the 600w, if the attic is vented heat shouldnt be an issue seeing the cold weather is coming.

bollocks thats how normally they bust you in the UK at least, thermal images of roof tops couple of fly pasts over a city and they know who's got what, be very carefull with attics those lights give off a massive heat i have a 400 and thats air cool but i wouldnt pick it up after 12 hours on, too hot, you dont need more than 400 hps to grow personal i have dont it for the past 10 years with a 400 and produce the kind of nuggets to be proud of

bongo said:

bollocks thats how normally they bust you in the UK at least, thermal images of roof tops couple of fly pasts over a city and they know who's got what, be very carefull with attics those lights give off a massive heat i have a 400 and thats air cool but i wouldnt pick it up after 12 hours on, too hot, you dont need more than 400 hps to grow personal i have dont it for the past 10 years with a 400 and produce the kind of nuggets to be proud of

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i don't have much choice as i live in a 2up 2down and the roof is the only space i have...do you know if there are any ways to reduce or hide the image

600's rock, you can get reflectorized bulbs for 600watt lamps and you can get about 1lb yeild off one...

400's are cool too, you can still get the reflectorized builb, but you don't get as much yeild maybe 10oz at best.. the plus side to a 400 watter is you can get one that is switchable from a metal halide bulb to a high pressure sodium bulb... that way you can use the same ballast for both veg and bloom...

you may be able to get some kind of metal halide conversion bulb for a 600watter, but its going to be more pricy

crazy-mental said:

when i had a 250 i then wanted and needed a 400 now i wish id got a 600 or a 1000. but thats just life, always wanting what we havent got.

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Had to look twice at this last post!!.....thought you guys were talking about motorbike engines, cc! It got my attention anyway!

I have a 1100 by the way.....and I am talking about motorbikes!

all i ment is that i always need more lights, cos im always growing too many plants and always need more light. durban poison wtf i thought this was a cannabis site. nice man.thanks for that friend.
craige

crazy-mental said:

all i ment is that i always need more lights, cos im always growing too many plants and always need more light. durban poison wtf i thought this was a cannabis site. nice man.thanks for that friend.
craige

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No worries...lol. Just thought it was funny, came across the words "Got a 250 but wanted a 400, now I wish I had a 600 or 1000"....first thoughts were "Hmmmmm, wonder what bike He's got then".....Sorry.....hehehe....sorry

In my experience the 600w HPS was at least 2X hotter than the 400w. Yep call me crazy my space my space is a little smaller than most. Lumatek ballast for the record, which didnt run as hot as I expected.

I use 600 watt digital ballasts now and also have 4 400 watters I used to use. Not much difference in heat actually the 600 watters are cooler in my expirence. I run 2 600 watters verses 3 400 watters and temps are lower. You can get a 600 watt digital switchable ballast at Maryland Hydroponics for $119 it digital and runs either hps or mh bulbs.And yes there are now 600 watt mh direct bulbs no need for exspensive conversion bulbs.The 600 watt mh bulbs are around $40 each new.I posted a link to them awhile back.The 600 watt light adds so much more light and coverage and since its digital useless energy almost the same as a 400 watt magnetic ballast.If your worried about heat detection which must be more of an issue overseas as they have to have a warrant in the states to scan a home you can always line your attic ceiling with reflective heat duct insulation. It comes in rolls and is shiny silver. It reflects heat and xray scans.

X-Ray scans? Are you serious?