Lighting 400w hps/mh

[Nate4twenty]

I have a few questions on lighting

I plan on going with a 400w hps/mh set up for 32x32x63 space.

I would like to grow 3-7 plants at a time.

Ive also looked into CMH. I found a nice lighting set up on ebay with a remote CMH ballast. It cost about $100 more, but i uunderstand you dont have to switch lights, and with summer coming up, it helps with heat problems.

For ventilation i have a 4in inline duct fan with carbon filer and an oscillating table fan on the inside.​

Lighting:

• What would be my best choice here?
• Can i start the seedlings under the selected light choice, or will i have to go with something softer?
• How far should i keep the light away from the seedling/plant?
• Do i ever have to change the bulbs for a different light spectrum?(mh/hps) If so, when?
• How many plants can i manage under the chosen 400w light?

 

[pop22]

I've done some reading and the value of those dual bulbs is questionable. Most modern digital ballasts will run either an MH bulb, or an HPS. Even with that, you can do a whole grow with just an MH or and HPS. I used a 600 watt MH and had a very good grow, getting 6oz from one plant, and it was my first grow! I ran MH all the way thru with excellent results. Even better, 400 Watt bulbs are not expensive, buy one of each and switch them at flowering. But it is not necessary.

You can use the light with your seedlings, if you have enough space to raise it up 30" ( 76 Cm ) or even a little higher if you can. I have 16 seedlings under my 600 watt right now and they are doing fine. They are now about 4" tall, and I've lowered my light to 24" You would want to drop to about 20" You can keep it about there, if you can right into late flowering. Some people run them closer, but it will keep the heat stress to a minimum and still give you great plants.

:Sharing One:

depends on what strain you plant 4 to 6 with ease, I'd say 8 max.

 

[Nate4twenty]

Thank you for the fast reply. This is all i needed. Im gonna commit to the grow and purchase the needed items! Ah the nervousness/excitement.

 

[BillyMadison]

7.84 SQ ft with a 400w HID. Heck yeah man, that's 51 watts per square foot.

I would use the mh for seedling veg stage (first 5 weeks~) then throw that hps on.

I say do 5 plants. 1 in each corner then 1 in the middle.

 

[KannibisKing]

4 plants, switch your bulb over at week 4-6.(or whenever u prefer).

 

[BillyMadison]

4 plants, switch your bulb over at week 4-6.(or whenever u prefer).

This is more realistic IMHO. 4 max in a 32"x32" . Also control the size of your plants with container size. A 3 gallon container can have a width of 10" but the plant can get 3x that width.

Get a good stable auto that doesn't mind being SOG'd. Many breeders specify "great for scrog or sog"

 

[devils lettuce]

im doing a grow similar to yours . i have 2 400w hps bulbs for veg and 400w hps for bloom. i will have them in 2 yieldmaster II 6" reflectors on a switchable twin ballast .in three gallon pots

i just got a mixed pack of auto fem seeds from herbies. since i have never grown before i kinda wish i would have learned with a photo plant .cause damn these seeds were not cheap..