One HPS light per how many plants?


#1

I’ve been thinking of upgrading my light to one 600 Watt HPS with 89,000 lumens sometime after Christmas.How many cannabis plants will I be able to grow with it? Right now I have 3 seeds I planted on Sunday,5 in the veg stage and 3 in the flowering.Growing this many under 2-4 foot flourescents is pushing things a bit too much.
BTW my Northern Lights are coming along quite nicely,I see I have buds in the early stage of flowering.I should post some pictures once I turn off my meta tags on my phone.
Thanks.


#2

I hope you get your lamp in time to take advantage of the good genetics you bought.

How many plants you can grow under a 600w HPS is a matter of grow methods, grow systems, and techniques used.


#3

I’m growing my plants in soil in 10 liter planters in a spare bedroom that I’m not using for anything.I have my lights hung up from the ceiling and can adjust the lights as my plants grow.I doubt I’ll be getting my light in time to use on my Northern Lights since they’re in the flowering stage but my other plants will benefit from the new light.Is a grow tent necessary? The walls of the bedroom are painted with a gloss white so my plants should grow good.
Thank you.


#4

A 600 watt HID is good for about a square meter, about 3 foot by 3 foot, and up to about a 5 foot by 5 foot area, most people seem to use them for a 4 foot by 4 foot area.

Depending on how you grow, train and prune you can squeeze the following number of plants under a 4’ X 4’ area with intense lighting:

25-36 four liter/one gallon pots, 5-7 days vegetative growth
9-16 eight liter/two gallons pots, 10-14 days vegetative growth
6-9 twenty liter/five gallon pots, 14-28 days vegetative growth
4 forty liter/ten gallon pots, 21 to 42 days vegetative growth
1-2 eighty liter/twenty gallon pots, 28 to 56 days vegetative growth

I adapted the above from an article I recently found on High Times magazine:

http://www.hightimes.com/read/insiders-grow-planting-density-spacing


#5

BTW, a tent or Mylar isn’t necessary. Flat white paint is the best, better than gloss paint and in some instances, flat white paint is better than Mylar, especially under HPS where Mylar or other “mirrored” surfaces could possibly focus the HPS light and you would get “hot spots” and burns, not that unlike a magnifying glass focusing sunlight. However, having the white walls close, bordering this 4’x4’ area, is important to keep from wasting light. In other words, if you have all your plants under the light in a 4’x4’ space but this is in the middle of a 8’x8’ room, a lot of the potential light is wasted as it can travel so much further before it is reflected back towards the plant. This of course is only really important if you are trying to maximize the growth per watt of electricity used. It wouldn’t be as efficient but you could grow in a bigger footprint if you want.


#6

I love the idea you mentioned MacG. Any area that you can paint flat white, and have decent temp control will allow you to grow excellent Meds. :slight_smile:


#7

I’ve decided that I might as well bite the bullet and order the HPS lamp now instead of waiting any longer.
I had a minor disaster this morning,I was raising my fluorescent lamps and the power cord tipped over 2 of my seedling pots,the seedlings didn’t look to be damaged at all so I added a little more soil to replace what was lost.I just hope they’ll survive my clumsiness.


#8

For future re: PLease do not drape chords and such all around your grow. Buy 2-3 different sizes of zip ties, and strap them out of the way.

We hate to see you lose you genetics; Or worse; 8-O Get hurt.

Good for you. Look forward to seeing you grow successfully. :slight_smile: