3 x 315 W or 2 x 630 W of CMH

[mucki]

Hi everybody ,my first post after 2 days of reading about CMH.
Thank you all for unlimited information

My question is :
for 4 x 8 footprint what will be better: 3 x 315W units or
2 x 630 W. I have a hard time to decide. Your help will be appreciated

 

[kelly1376]

What type of reflector would you be using with the 2 x 630?

 

[mucki]

I have a choice of 630W DE CMH or 2 x315W reflector

 

[mucki]

anybody??

 

[Koondense]

Check the footprint data of the reflectors and see how it fits your space, my guess is 2x 630 is a better option any day.

 

[kelly1376]

I'd run the 630 in a big parabolic vertical hood like this one:

https://www.amazon.com/gp/product/B00QR3SA1K/ref=s9_acsd_hps_bw_c_x_12

Two of those will cover your 4 x 8 nicely. Big vertical parabolics are very under-rated.

If you were gonna run the single 315s your best setup would probably be picking up another 315 and running them staggered like this:

oxox
xoxo

x= light
o= empty space

The problem with the 315 is it really only covers 3 x 3.

 

[mucki]

Thank you guys

 

[mucki]

I will go with 2 x 630W .The last question is 630W DE or 2 x315W fixture?

 

[kelly1376]

IMO only run the dual fixture if you outfit the dual lamps into your own reflector of choice. Something like a dual bulb raptor. You can get a mogul to CMH conversion for the reflector pretty cheap. The dual lamp ready to go reflectors currently selling are kinda small and you'll probably get a bad hot spot and uneven coverage. You need a big hood to get good coverage. I mentioned the vert parabolic earlier check out vapedg13 parabolic grow using that hood getting 2 lbs per light off cheap metal halide:

https://www.icmag.com/modules/News/showarticle.php?threadid=243060&page=3

Also this guy ran vert parabolic over 5 x 5s in sog and averaged 3 per light:

https://www.*********.com/community/threads/soil-sog-grower-needs-mentor-to-switch-to-hydro.25499/

 

[kelly1376]

Sorry that 2nd link didn't work:

http://************/zczswqn

 

[mucki]

Muchas gracias

 

[GoldenSyrup]

I will go with 2 x 630W .The last question is 630W DE or 2 x315W fixture?

Go with 4 x 315w fixtures for the entire space - the DE lamps offer less PPF over all than the SE 315w fixtures do. Plus you'd have more points of light which means better canopy penetration.

 

[Dozee]

I just ordered me 3 -315w. Not here yet but excited.