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#1 Janw



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Posted 03 May 2019 - 09:28 AM

Hi guys I’m very new to this and need a bit of help I have a 60x60x120 grow box I have all I need except the growing light, there are so many out there I need help to get the right one, I’m going to grow medical cannabis if that helps, jan xx
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#2 2scoops


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Posted 03 May 2019 - 10:07 AM

Either an older 400 or 600 dual spectrum hps or even better a dimmable 250, 400 and 600 hps summink like a lumi (alot easier to control temps then in hotter summer) or an LED which lots of growers seem to be moving too today, the latest and best LED im led to believe are the Samsung quantum LED or COB led. Hps lighting you could pick up pretty cheaply in comparison to LED. Both those lights will produce you plenty of nice buds as most growers will tell ya.


Picking right LED can be a minefield so beware of that one. A member here named Forest builds decent Quantum or COB leds cheaper than you could get other places, that maybe worth a look if you go that route.

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#3 denots


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Posted 03 May 2019 - 11:02 AM

Hi Janw, welcome on board mate.  As Jimmi says really, 250 to 600 hps dimmable ballast, or led mate. As in led's the choice is vast, but our Forest won't put you wrong he makes some fine lights mate.

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#4 Forest


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Posted 03 May 2019 - 01:33 PM

@Janw   for a 60x60 tent a 250hps suits  or if you want led there is a few choices  on ebay this will suit a 120w  3000k  147 quid https://www.ebay.com...984.m1555.l2649


and it will out do a 250w hps


or send me a pm and its a bit cheaper

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#5 Viz


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Posted 03 May 2019 - 04:47 PM

Hello @Ganw Forest is without doubt the go to guy for quality LED fighting.

I quickly did the maths re your set up. The size of your grow box is going to get very warm, very quickly doe to the size if you go the HPS route. Even the 250W is going to be like a heater in that small space. Assuming you are EU/UK based with summer about to kick in. Temperature is going to be a factor.


Heat Generated by a Grow Light
New lighting technologies, such as CDL and LEDs generate light more efficiently, or with higher efficacy than incandescent lamps. In other words, we get more lumens per watt; however, heat per watt of electricity is constant. Fewer watts are used to produce equal brightness, not that CDL or LED light fixtures produce less heat for the wattage that they consume.

1 watt of electricity produces 3.412 British Thermal Unit (BTU) of heat per hour regardless of light type incandescent, HPS, CDL, LED, fluorescent, induction, etc. Therefore, a 1,000W HPS grow light (1,060W with ballast loss) generates 3,617 BTU per hour heat. A 500W LED grow light (550W with driver loss) generates approximately 1,877 BTU per hour heat. A 315W CDL grow light (335W with ballast loss) generates approximately 1,143 BTU per hour heat.

Physics of heat
British Thermal Unit (BTU) is the unit of heat energy. One BTU is the amount of heat needed to cool or heat one pound of water one degree Fahrenheit at a constant pressure of one atmosphere, equivalent to 251,997 calories.
The heat dissipated by an AC power operated electrical device is equal to the AC power dissipation per unit of time. Heat dissipation in BTU/hour is calculated by multiplying AC watt dissipation by 3.412:

1,000 W (1 kW) is equivalent to 3,412 BTU per hour.

1 kilowatt-hour (kWh) is equivalent to 3,412 BTU.

How good is your extraction fan?
How much fresh air is available to your grow box?
What are you planning on growing in?

Will check back a little later.

Edited by Viz, 03 May 2019 - 04:57 PM.

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#6 uk Percy

uk Percy

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Posted 04 May 2019 - 05:13 AM

Hello Jan welcome.
I had a 250w in Same tent when started.
Aslong as you have right extraction and the room is cool your be fine.and good intake
Or even better beat the daytime heat and bring lights on a night to bring temps down.
I no run a 80 or 70 by 1.2 black orchid
I've just brought my self omega 250w-660w dimmable light and ballast.
I grew good flowers on 250w sumnaster.
Omega light set up was 100quid I got this last week.
Have good day.

Edited by uk Percy, 04 May 2019 - 05:17 AM.

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