HPS and CMH lights in flower?

New to hps and cmh. I bought two ballast and have them both going at the same time in a 8*10 ’ grow room with a portable ac and exhaust for cooling. My question is, should I be running two hps bulbs or will I get better results with the cmh and hps combined? I have another 1k hps bulb so i wouldn’t be out to upgrade If it is an upgrade. Also, would it be wise to rotate the plants in my current setup? ! Brw my plants are in week 5 of flower

Thanks in advance!

4 Likes

How many total watts? 8x10 is a pretty big footprint you’re gonna want probably 5K total watts for that space, CMH, HPS, or a combination of both. A 315 CMH to me, equals about 400 watts of HPS since it’s more efficient. If you have the money, invest in CMH. It’s just 5K watts of CMH is $$$ compared to HPS. 5K watts of HPS can be done for $1200, equivalent amount of CMH will easily be double that.

It really matters less than most would say, though. Cannabis just likes a ton of light, honestly rather difficult to overdo.

5 Likes

I’m super jealous of that monster space. Normally a 315w CMH is good for a 3x3, 1000 HPS 4x4 to 5x5 really depends on how much of that space you’ll have filled and how you’ll have it filled big plant or little/sog/etc. Like @vernal already said about 5000 watts for that space sounds bang on.

With those plants in the picture a 1000w HPS should be more then enough. I wouldn’t waste the money to generate more heat that the AC has to pull out of the system. FYI if I remember correctly that is a 1000w HPS generates about 4000 btu’s.

6 Likes

Agreed. If you aren’t gonna fill the space 100% extra wattage is just extra expense and wasted light. Depending on your A/C capacity as well. Better to have less light than 90 degree temperatures.

Also difficult to access all those plants for maintenance, if you are going to fill that space entirely you may want an aisle of sorts between plants. I can barely reach across a 4’ space and I have long arms.

Million ways to skin a cat, you’ll figure it out as you go. An 8x10 room is a full part-time job, expect to spend 20 hrs a week messing with it, but the payoff will be excellent, could be 5-10lbs per harvest depending on skill and method.

2 Likes

If it were my area and cost wasn’t a concern, I’d do two 4’x8’ OD trays in there, with two 1K HPS and 1 630 CMH in the middle per tray. This will allow some room between plants to access, but it will be tight in there. Tons of light too, should be wall to wall dense nuggets.

2 Likes

Thanks for the input guys! You both are right, why push more light than I need. Currently running 9 clones. Not gonna add more because j leave for Oregon next week to get married, and we will be gone for a week and a half. Went and added a drip irrigation system and timer. Also added a t to inject my nutrients from a separate reservoir using a small automatic watering pump. Have it setup to inject nutes 7 days after I leave, and 5 minutes before the water timer releases the morning water. So I should just keep it as is and not use the other hps and keep the cmh running? Would I need to rotate them considering they’re two different but similar lights? Both bulbs are only being ran at 750 due to heat. Got the room at a steady 75 for flower with 45 relative humidity. Luckily I started this crop early enough to beat the Oklahoma summer heat and humidity. Though it’s indoor the humidity still will affect it heavily here.

4 Likes

Currently running the 9 clones. I have the whole garage to expand too. The 2ne half of the garage has 14ft vaulted ceilings and open rafters. Already has roof vents for my exhaust and next ac. The ac I’m using is a 8k btu with dehumidifier. didn’t know if I should be rolling my plants around their trays and switching witch light theyre under.

1 Like

I’d make a good veg area to work in with that much space maybe a veg and dry area.

I would not worry about switching the light since head room doesn’t sound like a problem for you. You have an interesting setup there can’t wait to see more pictures.

1 Like

What’s the height of your room? That may be the deciding factor one vs the other. You can run aircooled HPS reaaaal close to canopy. CMH more or less is open hood, and while the 315s can get pretty close, a 630 might need some distance.

EDIT: nevermind I see they’re 14ft ceilings any option would work, DE 1K included.

1 Like

The current room is 8ft tall

1 Like

Not really sure the pic order bc I selected a group. I used tarp to frame up the room. Then used panda film to line the interior. Then used heavy duty all weather uv proof gorilla tape to seal the room completely. Along with spray foam crack sealant. 8k btu port ac. 2 x 6 inch ac infinity t6 , one in room for exhaust, one in attic with vent for fresh air in. Co2 hanging mats and 2 x 20lb c02 tank with controller. Rain bird drip irrigation system. Way cheaper than floraflex. No need for a carbon filter as my neighbors all grow and the exhaust is vented into the attic and through the sealing to a vented cap with odor killers. Not needed but figured the neighbors might enjoy a breeze of febreeze. And I have arm and hammer dehumidifier bags hung around the tent to kill some humidity outside the room . 2x chlorine purifier for rv Daisy chained . Reservoir with nutes tapped into the drip system on a timer. So 2 minutes before water comes on a oumoump pushes the pre loaded nutes into the line. And the magic happens when the faucet timer kicks in. Also have a humidifier and heater on timer if needed.

4 Likes

Sorry for the mess we leave in 6 days to get married in Oregon and life’s been busy lol. If anyone reading is near Portland or Brookings (we stay in both) I’d love to grab a cup of coffee and chat .

1 Like

The back half of the garage will need cleaned out and things out in the attic. Currently my 120lb American bully uses the futon to watch TV (hd projector and screen on the wall for football games.

Tent is 100 percent leak free. Light and air. Backgraft preventing vents installed in the exhaust and inflow lines

If you’re wondering my wife gets to buy all the makeup and shoes she wants. She gave me the garage and spare room for my fishing gear. I’m also a professional angler

3 Likes

Back to your lights if it were me if you’ve got 2 timers I’d set it up so they get both spectrums . A friend of mine is running cmh and hps on a light mover giving cmh for 4 hrs a day and hps the remainder of the day . His testing has showed improved quality (ie frost, terpenoids) of the buds with out loosing the bulk that hps produces .

1 Like

Would my single 1k hps push enough light for 9 plants alone?

1 Like

That’s very interesting on the results. I’m willing to give anything a try twice. I’m new to growing. This will be my 3rd harvest as this cannabis obsession has overtaken my brain. Started with a bag seed of white widow that I found. Went female, then hermied. 2nd grow was train wreck and bubba kush in a 4 x 4 I. Our house with a single led

Pro angler? Maaaan so jealous. I’d be happy to qualify as amateur.

Basically same boat. I don’t always understand my wife’s purchases but at the same time try explaining why you spent $1K on blow, weed seeds, and glass.

2 Likes

Nothing cool about being pro I promise, just bigger bills and bigger entry fees my man. Battle for sponsors, not that fun. I love growing weed though. All my money goes to the wedding first, grow, my dog, then fishing. Lol but my number one collector is her, actually Ulta beauty lol

2 Likes