First Timer With Light Questions

[dejayou30]

A friend of mine is planning his first grow and I am kind of helping him, or doing what I can. He is using an E&F system for 10 plants. He doesn't have internet access and wanted a few questions answered:

1) How many 100W CFLs would be sufficient for 10 plants to veg under?

2) How long should they stay under the CFLs before switching to his 1KW HPS light so they don't burn?

3) Would putting the squirrel fan intake under the hood (but not like a cool tube, just put it under the hood) do a lot to help with the heat as opposed to just running the fan in the open air.

The room is only 5x10 (he is only using about 3x2) and he is worried about how much heat that 1KW is going to pump out.

Thanks for any help anyone can provide.

dejayou30 Reviewed by dejayou30 on 09-04-2007. First Timer With Light Questions A friend of mine is planning his first grow and I am kind of helping him, or doing what I can. He is using an E&F system for 10 plants. He doesn't have internet access and wanted a few questions answered: 1) How many 100W CFLs would be sufficient for 10 plants to veg under? 2) How long should they stay under the CFLs before switching to his 1KW HPS light so they don't burn? 3) Would putting the squirrel fan intake under the hood (but not like a cool tube, just put it under the Rating: 5

[Dutch Pimp]

Very tricky questions...does he already have a 1000HPS light?...but not the CFL's?..a 400 or 600HPS would be better.

You CAN veg under HPS too. Generally, you veg the plants for about 30+ days, until the plants are 12-15 inches tall. But everyone says veg under 6500k cool white CFL's (I never tried it)

Now comes the hard part...HEAT. Test the grow room temps..BEFORE you pop the seeds. Get a battery thermometer, one that records high/low temps and humidity. The objective is to keep the temp at the top of the plants at 75-85 degrees and around 50% humidity. It's not easy. 3x2 is very small for 1K light. Most people that do this alot, use A/C and have good air flow.

There are many, many other issues to go over. A grow guide will cover this. There a several available on this site.

[dejayou30]

Well, here's the deal. He got the 1KW ballast and a brand new Hortilux bulb for $75 total. Obviously, its a big light for such a small space and there are a lot better options, however, for the price we got it was just too good to pass up.

He also has the temp gauge that shows the temp and humidity at the thermometer and keeps track of the high and low of both over the past 24 hours. The unit also has about a 30 foot cord attached to read the temp wherever the end of the cord is and I get the high/low temp from that as well, so being able to tell precise temperatures through the room is pretty much figured out.

As for the layout, it is an E&F system sitting on a 3'x2'x2' table at the narrow end of the room and there is mylar around all three sides. The front side of the table is open to the other 8 feet of the room. He has a squirrel fan that the guy he got it from told him clears a 10x15 room in an hour. He has the intake of the fan under the hood, and another fan blowing from the opposite side to circulate air under the hood and move it towards the intake of the squirrel fan. There is also a 20x20 filtered passive intake for fresh air.

He won't let me take pictures, so I drew and attached this crude diagram. We've both done our fair share of reading, but there are some extraneous things we have questions about that aren't covered in reading. Feel free to make suggestions based on the diagrams provided. We have considered leaving both the long sides open and putting the short end against the wall, but then we would lose the benefit of having the mylar right up to the side of the table.

Also, he wants to veg under CFLs until the plants are able to withstand the 1KW, however long that is.

Hope that extra info will help, let me know if you have other questions!

[dejayou30]

Anyone?

[Dutch Pimp]

but there are some extraneous things we have questions about that aren't covered in reading. Feel free to make suggestions based on the diagrams provided.

how much space is there between the top of the table...and the ceiling?....what kind of extraneous things?....

veg cycle is 30+ days on average. 12-15 inches tall.

[dejayou30]

The ceiling is I think 6'8", so there is about 4 to 4.5 feet from the top of the grow tub to the ceiling. I know how long to veg the plants, but what I am wondering is at what size or how many days will they have to be under the CFLs before we can throw on the HPS. I don't want to fry the seedlings but I'd like to get the better spectrum from the HPS asap.

Also, what do you think of my setup? Will it be enough fans to dissipate the heat? We were also going to put an oscelating fan in the middle of the room to blow back and forth across the table.

[Skrappie]

I see dutch is dishing out time tested advice again. Dejay, I have about 10 guides that i'd be more then willing to either upload or email to you so that your friend can have those on hand.

now, on to actually reading the post

[Dutch Pimp]

but what I am wondering is at what size or how many days will they have to be under the CFLs before we can throw on the HPS.

You can veg. cycle as long as you want too, under the CFL's, but most growers veg for 30+ days, 12-15 inch tall plants. The light cycle will be 18/6 or 24/0, growers choice. Then you start the 12/12 flowering cycle (check indoor lighting forum, about CFL's or Floro tubes))

The ceiling is I think 6'8", so there is about 4 to 4.5 feet from the top of the grow tub to the ceiling

Your're not gonna have much space left, after you hang a 1K light. And the 1K light will have to be at least 20 inches from top of the plants, maybe more. This is the space you HAVE to keep at 75-85 degrees.

Hi Skrappie...I'm really not very good at advice. I'm a master smoker, not master grower, but I try to help out here and there...imp:

[dejayou30]

You can veg. cycle as long as you want too, under the CFL's, but most growers veg for 30+ days, 12-15 inch tall plants. The light cycle will be 18/6 or 24/0, growers choice. Then you start the 12/12 flowering cycle (check indoor lighting forum, about CFL's or Floro tubes))

I think you're missing the question here. I understand completely about veg cycles and all that. He wants to veg under the 1KW AND flower, but the 1K will burn the seedlings or so we were told.

Your're not gonna have much space left, after you hang a 1K light. And the 1K light will have to be at least 20 inches from top of the plants, maybe more. This is the space you HAVE to keep at 75-85 degrees.

I'll still have about 3 feet or so if I keep them at 20", so I don't think it will be that big of a problem. I am still wondering if the three fans will be enough to keep it cool, though.

[PharmaCan]

Why don't you ask your friend what he thinks is the advantage of vegging under the hps? Then, when he tells you because the light spectrum is better, tell him he doesn't know what he is talking about because he can get a better vegging light spectrum from cool white cfls and the plants will veg better under cool white cfls.

There's only one way to tell if your ventilation will work - try it out! Now, so you can make any changes.

PC :smokin: