MH & HPS Question

I was going to use 2 600w HPSs for my grow. 5 BlackJacks in a 8L x 4W x 5H. Do I need to use a MH for veg or can I just use the HPSs for the whole grow?

If you have the MH available then its always preferable to use MH during veg because of the color temperature, but if you only have the HPS then its fine to go all the way through with just that. With 2x600watt HPS you'll have more than enough lumens for 5 plants, if anything its a bit much, just keep your temperatures in check as that small of a grow area with that much light you'll have heat issues unless you are sucking it out like a banshee.

Just trying to get a good yield. so with that size box, you think I should only get one 400w MH for veg? And for the HPSs I plan on doing cool tubes and probably a little a/c unit.

Yeah your fine using the hps if that all you got. It better then florescent lights if you can keep the heat down. Just start off with one I don't think you'll need the 2nd unless you want monsters.

I just figured a long box at 8' I'd need 2 lights to cover them all equally.

404NotFound said:

I was going to use 2 600w HPSs for my grow. 5 BlackJacks in a 8L x 4W x 5H. Do I need to use a MH for veg or can I just use the HPSs for the whole grow?

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My personal opinion is that warm range MH bulbs are best around 3200k, and yes you cana just use hps all the way through, but its best to use mh for vegetative then just add the hps to it,

ok if your going long, maybe rig up the mh in the middle as a vertical light, itll improve surface area

Prefontaine said:

My personal opinion is that warm range MH bulbs are best around 3200k, and yes you cana just use hps all the way through, but its best to use mh for vegetative then just add the hps to it,

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So you're saying leave the MH in and add the HPS when I switch to flower?

This might sound like a noob question but MH lights get hot enough to where it'll need a cool tube?

404NotFound said:

So you're saying leave the MH in and add the HPS when I switch to flower?

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Sounds like a good idea to me. More lumens = more bud, its just a fact of growing

So basically 3 lights, 3 cooltubes hps's on both sides of the vertical mh....not a bad idea everyone. I like it.

404NotFound said:

This might sound like a noob question but MH lights get hot enough to where it'll need a cool tube?

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If your grow area is ventilated well(exhaust fan), then probably not when its alone, but if you have no other ventilation then yes. The idea behind cool tubes is a two factor thing, 1) to reduce the overall temperature of the lightbulb itself to increase its life and 2) suck the heat out of the area instead of transferring it out towards the plants.

404NotFound said:

This might sound like a noob question but MH lights get hot enough to where it'll need a cool tube?

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a MH gets pretty warm i have a 400w MH(no cooltube) and i keep the ac on or it gets 95+ in a 3x4 grow space you'll want to get some good ventilation in there

So when I hit the flowering stage with my plants, I'll want cooltubes on all of them to take the heat all out, Would I have to have a ventilation then?

In a closet with an HPS on one side, and a MH on the other, plants placed between the two lights seem to lean over towards the MH.

I only use HPS start to finish I've used MH bulbs, but by the time I switch to flower climbing around plants and pulling the heavy glass out my my hoods is less than efficient, so I stopped changing bulbs and only stick to HPS bulbs, its just easier and not much difference, also ask yourself how long your going to veg for, I veg 7 days from clone and switch the timer to 12/12, therefore not so necessary for the MH bulbs, if you're planning on vegging some beasts and plan to veg longer than 2 weeks I'd consider using the MH bulbs, all in your configuration and motivation.

Well I'm going to do scrog, so I'll be vegging until most of the scrog is filled up and then switch it over to 12/12, so I'm thinking about maybe 4-5 weeks in veg. I'll just stick to the 2 HPS on either side and the plants will just lean towards whatever light is closest.

So with 2 600w HPSs in a 8L x 4W x 5H with cooltubes, will I still need an exhaust or will I be fine with just the tubes?

Kinda sounds like you should do a LOT more reading about what is needed for a basic grow. Once you understand how to setup a basic grow, then you'll be well on your way to doing it right. You are trying to set up a specific environment & need to do whatever special steps to insure your space meets the needs of the plants. I've been working on my setup for a month now & about another several weeks from just turning on my room to check it.

Well, I'm also in the process of still getting all my materials and just trying to figure out exactly what will be needed and if I can cut some things out the way then so be it. I've done a lot of reading, just trying to see what everyone uses and see if I can get some positive feedback on everything.