Advice 315 cmh + 150 hps 3'x3'x6'

315 cmh + 150 hps 3x3x6 First Grow Advice and Tips

Hello! I’m completely new to growing but decided I’d dive into it. I have read about many different lights and have decided to stay outside the realm of led completely. I was highly interested in cmh and have read that the 3,100k delivers a great blue spectrum. I also read of grows consisting of mh and hps lights to get a more full spectrum of light. So I was hoping I could use a 315w cmh from Sun System and a 150w hps also from sun system.

This is where I’m hoping for advice, how far would I leave the combo of lights from the canopy? Both cmh and hps are known for heat production, will my climate be too hot or dry? The cmh light comes with a control setting, would I have to lower the cmh to us the hps as well? I’d also like any advice that can be given. Here’s what I got;

• Vivosun Mylar Hydroponic Tent 36x36x72

• iPower Ventilation and Odor Control Kit 6" 350 cfm - It comes with a fan variable speed controller, carbon filter, ducting, temperature and humidity monitor.

• 2x 6-inch Hurricane Classic Clip-on fans

• Titan ControlS Apollo 8: Two Outlet 24 Hour Timer

• Sunlight Supply Sky Hook Light Hangers Pair Pack of Two

• Sun System Hps 150w Fixture with Ultra Sun Lamp

• Sun System Lec Boss 315 Watt Commercial Fixture With 3,100K Lamp,120v/240v

•2x Active Aqua Root Spa 5 Gallon Hydroponics Bucket System

• BlueLab Grower’s ToolBox - This has specific pH up and pH down, as well as a ppm pen and a pH pen

• General Hydroponics pH control kit

• General Hydroponics Flora series - 1x Qt FloraGro 1x Qt FloraMicro 1x Qt FloraBlossom

• Mother Earth Hydroton Original Clay Pebbles, 50L

• GGT Heavy Duty Trellis Netting For 3x3

• General Hydroponic Rapid Rooter Replacement Plugs

• Shear Perfection Gold
Series Straight Trimming Shear, 3 in.

• APC Surge Protector Power Strip with USB Ports, P11U2, 2880 Joules, 11 Outlet Power Strip Surge Protector.

If you are going to use a hps during flower I would go with the 4000k whatever cmh. Use cmh for just veg and soon as stretch is over during flower add the hps

Alright thanks man I’ll give it a go👌

The cmh is far superior light to just about every hps other than a de gavita. If it were me, I wouldn’t even bother with the 150. It has about half of the efficacy of the leading cmh bulb. Anything smaller than 600 watt hps really tanks in efficacy. The 315 alone is good for 3x3 all day long. Not sure which bulb is included with your fixture, but last I knew Phillip’s was the best. Mater green power, or something along those lines. I’m led guy, but plenty of people I’m close with use them.

Most cases that you see cmh and hps mixed together the hps has the primary lighting duty and the cmh is added to balance out the spectral distribution. These are typically big rooms using those monster hps lights, where there isn’t really a competitive option in cmh.

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Why shy away from LED?

@dbrn32 thanks for the input man that’s exactly what I was thinking, but I looked at the recommended distance from canopy and the 315 cmh has to intense of light for the vertical room I have to grow.

@Arborfarms At first I wanted the most dense buds I can get but after a closer look at the room I have I believe LED may be the way to go for me.
Would you personally go for Kind or California Light Works

You’re in a 6’ tall tent, most are usually 5’ or so and plenty easy enough to grow with cmh. You just need to manage plants accordingly, which is more like something synonymous with indoor growing. Regardless of light you’re using.

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If you look at my most recent journal, I have the exact same tent. A “true” 300 watt light is perfect for the size of that tent. I personally use HLG and I have had amazing results with them. My last journal entry here was a single ScroGed ILGM cherry pie pulled in 1.45g/per watt @ 300 watts. Spider farmer is a good light manufacturer with a very attractive price,

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@dbrn32 I read the best way to calculate plant room is to take the total room subtract light size subtract bucket size and finally subtract the distance the light has to be from the canopy. For me 72-5-15-24 leaving me with a 2 foot plant. Is this adequate room for a plant ? Any advice would be great because I do like the stats I’ve seen from cmh lights

@Arborfarms that plants looks great! And to be done with a single led, gives me real faith in LED lights. I’ll make sure to check out Spyder farms as I’m almost sure the price is better than kinds 400 dollar light.

Thanks bud!

Check this link -

I’ve never seen a formula like that, it seems more complicated than it needs to be. A common sense approach to what you have and how you plan to grow should get you to where you need to be.

Install your fan and filter in top of tent however you intend, then place light in and raise as high as you can. Measure from bottom of light and deduct the minimum distance recommended to run your light from canopy. That’s essentially what you have left to work with.

Let’s say it’s 3’ and you plan on running with a pot that’s 12" tall. Then yes 2’ tall plant is what you would be shooting for. If that’s the case, you would maybe want to look into running a scrog. You could see up screen 16" above plant and give yourself some wiggle room, that would be plenty of room.

Other things you could look at is using shorter pots to gain you some room. Altering your fan and filter placement to get more head room. Or maybe running more plants in order to fill the canopy with short plants instead of trying to fill the space with less larger plants. I believe @bogleg said something like growing indoors is more about how well you can get your stuff to work than actual gardening. A lot of truth in that.

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You won’t ever catch me endorsing spider farmer, but I would much rather grow with a $300 spider farmer than a kind light that costs $1000.

The light looks good, I’m not sure if it’s pictures or just the spectrum of light but I can’t see to much blue on the light. Over all even if it’s missing blue lights, figure could always use cheap t5 lights to supplement for veg, and the ppfd is pretty great for small tents.

I think your right, I probably should just feel it out all together as far as the light distance. Also as I read more I see how capable cannabis is, and understand more the idea of making an indoor grow work is the heart and soul of indoor growing not just that your growing indoor.

Also to me you being a long term member comparing the spider farmer sf2000 to a kind k5 just about has me sold on the spider farmer.

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I recently helped a friend mount a Spider Farmer SF-4000 in her 3x3 tent, I was pretty impressed by the light and the fact that it was pulling 443 watts (using my kill a watt monitor) from the wall.


Thoughts on if I were to put 4x 24w 3000k on the corners of the tent with the spider farmer sf2000 for veg and after stretch flip to 6500k bulbs in the t5s?

That spiderfarmer light is a “full spectrum” light, no additional blue is needed for veg. It also comes with deep red 660 diodes to aid in flower development which is a huge benefit. The light uses the same samsung lmb301 diodes as hlg does, hlg just uses top bin versions of the diode, for simplicity reasons think of the difference between regular Unleaded gas vs super unleaded at the pump. Both diodes are great, top bin is just a bit better.
You honestly can’t go wrong with the light, it’s damn near a copy of an hlg light at a fraction of the cost. When i bought my hlg spider farmer wasn’t around or i would have bought the SF 4000 in a blink of an eye.
With the light price low, it frees you up to put more money into perhaps a “pulse@ grow monitor (highly recommend this, and use the DGC code found on dudegrows) to got a savings. Your light is important, but your environment is even more important. You will need a minimum 30 pint dehumidifier for that tent. I don’t care what anyone else says, i have that tent and in order to get the RH damn near perfect i had to get a bigger dehu, saving money on the light will allow you to do this.
If you need any help, let me know. You basically will have a similar setup as i did and you will be smashing yields per plant (grams/watts) like i have been. Happy grows growmie!

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The feedback for the spider is overwhelming and thanks for the input guys. It’s definitely amazing to get such feedback and support. Thank you for the brainstorming and I’ll make sure to ask if I run into any problems!

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