400w vs 2x 250w

[bp420!]

I have a 2x4x8 ft grow closet would i be better using a 400w light there or 2 x 250w lights. Would two hps lights be better or a MH and HPS that just run simultaneously?

If i makes a difference i'm planning on about 8 plants in 3 gallon pots that will barely squeeze in that space.

 

[Heathinv]

If it was me I would use 2 lights, and 2 different bulbs.
For better spectrum, y'know.

 

[bp420!]

thats what i was thinking, just wanted someone to reassure me

 

[medi-useA]

I'm running 2 X 400W HPS in a 63 cm/24" X 120 cm/47" X 180 cm/70" cabinet. With an air cooled hood I can get down to within 10 cm or closer of the plant. Using a screen I can fill the screen with 1 plant or more if I choose. If I had a choice between 1 X 400W MH/HPS or 2 X 250W MH/HPS for your grow, based upon my exp. with my setup, I would choose the 2 light option.

This has several things going for it.
pro- 2 'sweet' spots!
pro- 2 lamps means you can vary the spectrum of light.
pro- 2 lamps means if 1 blows, the other will still be there.
pro- 25% more Wattage [and thus some more light] than 400W.
pro- potentially can have lamps @ different heights as needed.

con- must purchase 2 of everything {light fitting, bulb, ballast, cables,plugs etc...}
con- 25% more pwr usage than 400W.

check out my albums 'SkunkMix DWC under 2 X 400W HPS cab.'
and 'Vader's Visit' as well as 'random pics'. This is my cab and lights. And most recent harvest.

If you can get an air cooled hood or cooltube I would recommend it.

2 X 250W lamps is the way to go in my opinion...but keep browsing and asking questions, there are many opinions out there and soon yours could be one of them! hehehe

Let us know what you decide...

muA

 

[terrier]

go for two 250w they give less heat off and you could space them out more

 

[desert fox]

I say go with the single 400. Canopy penetration isnt that great with the 250. Its cheaper in the long run in respect to initial setup as well as having an extra 400 should you decide to upgrade later down the road. a Single 400 is nice tool to have laying around...250s not so much IMO. Also the single 400HPS will be easier to cool than a 2X250 MH/HPS and yield more. I like to keep things simple. The 400 should cover your area nicely.

here is some really good reading if your interested.
http://www.angelfire.com/cantina/fourtwenty/yor/yor.htm

 

[Roortokeage]

same thign from another guy, Are you trying to spend hella dough????
a 400 watt cool hoood will be your best bet take a look... It will produce less heat than 2, produce more light and 1 hood covers 4 square feet

HPS LIGHTING

 

[Jnugg]

same thign from another guy, Are you trying to spend hella dough????
a 400 watt cool hoood will be your best bet take a look... It will produce less heat than 2, produce more light and 1 hood covers 4 square feet

HPS LIGHTING

It will cover more then 4 square feet id' think the most a 400w will cover up to a 6 square foot or 2' x 3' garden.

He has 8 square feet so unless he can get a small light mover then 2x 250w is his best bet,unless of course he can keep ambient temps in check then he could go with 2x 400w HPS but he will need sperior ventilation and cooling as that would equal out to 100w/sq. foot and 12,500 lumens/sq. foot.

Personally I try to aim for a minimum of 62.5w/sq. foot and 7,500-8,000 lumens/sq. foot with a maximum of 80w/sq. foot and 10,000 lumens/sq. foot.

Now,if the closet/cab is not built yet and no wood has been bought/cut then I would advise a re-design.Make it 2' x 5' or 10 sq. feet or 2' x 6' or 12 sq. feet...this will put you in the money spot...

800w / 10 = 80w per sq. foot

100,000 / 10 = 10,000 lumens per sq. foot


800w / 12 = 66.66w per sq. foot

100,000 / 12 = 8,333 lumens per sq. foot


If the closet cab is already built or pre existing then there are a number of things you could do since it measures 8' tall.

You could section it off...400w HPS in a 2' x 2.5' or 2' x 3' (5 sq. feet - 6 sq. feet) area and setup a wall so you can use the remaining 2-3 sq. feet for a mom/clone area lit by T5's or a 150w-175w MH and go perpetual.

 

[bp420!]

I guess i should have specified that I currently have 1 250hps and 1 400 MH. I was trying to decied between buying either a 250mh or 400hps

1x400mh(veg) and 1x400hps(flower) // 6250 lumens/sqft and 50w/sqft.

2 x 250 hps through out the entire grow// 6500 lumens/sqft and 62w/sqft.

1 x 600w(+$50 over 400/250 ballast/bulb) // 11250 lumens/sqft! and 75w/sqft. I read that the sun on a clear summer day puts out about 10-12k lumens/sqft. Sun in a box anyone?


Decisions Decisions

 

[bp420!]

Check out 1000bulbs.com if you haven't they have really cheap prices:

600w ballast and bulb for $130 shipped.
400w ballast and bulb for $80 shipped.
250w ballast and bulb for $75 shipped.

Sometimes they have enclosed ballast other times ya just need to build a cheap metal box ta keep em in.

 

[desert fox]

I guess i should have specified that I currently have 1 250hps and 1 400 MH. I was trying to decied between buying either a 250mh or 400hps

1x400mh(veg) and 1x400hps(flower) // 6250 lumens/sqft and 50w/sqft.

2 x 250 hps through out the entire grow// 6500 lumens/sqft and 62w/sqft.

1 x 600w(+$50 over 400/250 ballast/bulb) // 11250 lumens/sqft! and 75w/sqft. I read that the sun on a clear summer day puts out about 10-12k lumens/sqft. Sun in a box anyone?


Decisions Decisions

I would say stick with what you have...a 250hps and a 400mh should flower and veg nicely. If heat is a problem I would stick with one or the other. HPS generally yeild more. MH for very dense nuggs. Dont forget conversion lamps. Price difference is negligible if you want to switch it up. no sense in trying to upgrade for that area.

 

[bp420!]

I would say stick with what you have...a 250hps and a 400mh should flower and veg nicely. If heat is a problem I would stick with one or the other. HPS generally yeild more. MH for very dense nuggs. Dont forget conversion lamps. Price difference is negligible if you want to switch it up. no sense in trying to upgrade for that area.

Did a quick search and found only MH->HPS bulbs, with the exception of the hortilux bulbs. I might not need to upgrade but if i'm going to have to spend the 100 bucks on a hortilux MH-HPS conversion makes more sene to just purchase a 400whps ballast and bulb.

is it ok to veg under a more powerful light than i flower under? Or are you suggesting running them both for veg and flower?

 

[Jnugg]

I guess i should have specified that I currently have 1 250hps and 1 400 MH. I was trying to decied between buying either a 250mh or 400hps

1x400mh(veg) and 1x400hps(flower) // 6250 lumens/sqft and 50w/sqft.

2 x 250 hps through out the entire grow// 6500 lumens/sqft and 62w/sqft.

1 x 600w(+$50 over 400/250 ballast/bulb) // 11250 lumens/sqft! and 75w/sqft. I read that the sun on a clear summer day puts out about 10-12k lumens/sqft. Sun in a box anyone?


Decisions Decisions

That sucks that you have a 250 HPS and a 400 MH,be better if it was a 250 MH and 400w HPS.

In the 2' x 4' area I would hang a 400w HPS...now you could take a 175w MH and take that cab....put a wall up in the cab so the flowering area measures 2' x 2.5' or 2' x 3' and use the remaining 2-3 square feet as a mother/clone area.

400/6 = 66.66w per sq. foot

50,000/6 = 8333 lumens per sq. foot.

Otherwise if not wanting to go perpetual I would pick up another 250w HPS and hang each one over the 2' x 4' area.....

500/8 = 62.5w per sq. foot

57,000/8 = 7125 lumens per sq. foot

So since you already have 1x 250w HPS and 1x 400w MH is either 2x 250w HPS or 2x 400w MH.


It does suck that the only MH to HPS bulbs are so expensive,the cheapest I found a 400w for was $108.

You could always go crazy and sell your lights and try to replace them with digitals....



Galaxy 400w HPS/MH Digital Ballast $140 from HID HUT

Lumatek 400w Digital Ballast $144 from HydroAsis

 

[bp420!]

That sucks that you have a 250 HPS and a 400 MH,be better if it was a 250 MH and 400w HPS.

I know

In the 2' x 4' area I would hang a 400w HPS...now you could take a 175w MH and take that cab....put a wall up in the cab so the flowering area measures 2' x 2.5' or 2' x 3' and use the remaining 2-3 square feet as a mother/clone area.

400/6 = 66.66w per sq. foot

50,000/6 = 8333 lumens per sq. foot.

Otherwise if not wanting to go perpetual

Decided against perpetual for this room maybe if i get a tiny bit larger area.

I would pick up another 250w HPS and hang each one over the 2' x 4' area.....

500/8 = 62.5w per sq. foot

57,000/8 = 7125 lumens per sq. foot

So since you already have 1x 250w HPS and 1x 400w MH is either 2x 250w HPS or 2x 400w MH.

This is what i'm going to do. I was able to pick up another 250hps and bulb for free from my buddy in return for some of my finished product lol.

 

[OGfarmerted]

dont you love those kinda trade offs

 

[bp420!]

That sucks that you have a 250 HPS and a 400 MH,be better if it was a 250 MH and 400w HPS.

Yeah I know

In the 2' x 4' area I would hang a 400w HPS...now you could take a 175w MH and take that cab....put a wall up in the cab so the flowering area measures 2' x 2.5' or 2' x 3' and use the remaining 2-3 square feet as a mother/clone area.

400/6 = 66.66w per sq. foot

50,000/6 = 8333 lumens per sq. foot.

Not really wanting to go perpetual.

Otherwise if not wanting to go perpetual I would pick up another 250w HPS and hang each one over the 2' x 4' area.....

500/8 = 62.5w per sq. foot

57,000/8 = 7125 lumens per sq. foot

So since you already have 1x 250w HPS and 1x 400w MH is either 2x 250w HPS or 2x 400w MH.

Yeah i worked a deal out with my buddy who has a 250w hps...hes going to trade it to me for some of my finished product

Thanks for you help jnugg

 

[bp420!]

yeah haha was nice saved me $100.

I bought this fan

http://www.businesslights.com/valueline-inch-435-cfm-centrifugal-inline-fan-p-2045.html

I'm thinking its over kill but it was cheap and got decent reviews...its like 1/2 the price of a similar vortex. I'm sure it will be a bit on the noisey side. Other than mounting it using bungie cord, anything else i can do to cut down on the noise?

Does it need to run constantly? or on set intervals like every 15min? maybe some type of thermostat that only runs it when it reaches a certian temp? prolly a little more costly than a simple timer but worth it if there is such a thing. I did a quick search and all that pulled up was computer fan temp controllers.

oh btw jnugg +rep thanks for the help

 

[qbert]

yeah haha was nice saved me $100.

I bought this fan

http://www.businesslights.com/valueline-inch-435-cfm-centrifugal-inline-fan-p-2045.html

I'm thinking its over kill but it was cheap and got decent reviews...its like 1/2 the price of a similar vortex. I'm sure it will be a bit on the noisey side. Other than mounting it using bungie cord, anything else i can do to cut down on the noise?

Does it need to run constantly? or on set intervals like every 15min? maybe some type of thermostat that only runs it when it reaches a certian temp? prolly a little more costly than a simple timer but worth it if there is such a thing. I did a quick search and all that pulled up was computer fan temp controllers.

oh btw jnugg +rep thanks for the help

If its for exhausting you'll probably want it on 24/7 to maintain negative pressure and keep all air flowing through your filter.

You could look into Speedster fan speed controllers or something like the Gro-Zone Temp-2V for the type of control you're looking for. But you will need to do more research to ensure that these controllers are compatible with your fan's motor type. Search around for posts by IamNotCrazy to find info on that.

 

[250wscrogger]

2 250's will be better than one 400 for that footprint for sure When using small lamps like 250's @ 1 plant per sq ft its often best to fim on the 4th node and lst the main shoots down for better penetration so the internodes turn into 6-8'' vertical buds after stretch. You can expect around 4-5oz a light if you do it right. If you really want to get 6-8oz a light and don't mind the numbers throw 32 clones in there in 6'' pots, veg 2 weeks and shoot for 14g per plant. Doing this should nearly double your yield while cutting veg time in half.

 

[bp420!]

thanks 250...i topped and lst them the day before i switched to flower...next time i'll start much earlier with my training.

Whats the easiest way to do a scrog with soil? seem like it would be a pain in the arse to unweave the plants each time i needed to water them. I only ask cause your name makes me think you have some exp in that department lol.

Also when should i start using molasses and how much/how often?