Is it ok to use both a 400w mh and a 400w hps at the same time in flowering?

[jin420]

Hello everybody, my main grow room(10ftx10ft) is in week two of flowering. Growing in drip totes, H&G aquaflakes nutes and have 4 girls trained into a roughly 6 ft. diameter canopy. Been using just 1 400w hps with 3 supplemental cfl arrays(4-100w eqv. bulbs per array). I have a eye hortilux bulb in the hps that kicks ass as it is but I was thinking about running my 400w mh alongside the hps instead of the cfls. Was thinking about lighting half of the canopy with the mh and the other with the hps then moving the lights to either side daily. As long as I can keep temps below 86F would it be better to run both hid's? Thanks for any help on this

 

[machnak]

I'd run em. I never had any problems running HPS and MH at the same time.

 

[jin420]

I'd run em. I never had any problems running HPS and MH at the same time.

Glad to hear that I've had some people tell me the mh would screw things up and that I'd be better off rotating the single 400w hps. That'd be a pain in the ass as I don't have a light mover. I can move them a few times each light cycle but it'd really help to have the extra light from the mh. I ran both last night and pretty much the whole canopy had direct hid light and the girls seemed a lot happier. I'd get another 400w hps but I don't have the money right now. This is gonna be my christmas bud grow so I want it to be good.

 

[Vache123]

I run a 150HPS and a 100MH in my cab now. Only got a single plant, but it's flourishing and it'd like to that at least some of that is due to the extra coverage. I've also heard that MH stimulates increases resin production, for whatever that's worth.

 

[Dirty Harry]

Using MH and HPS at the same time is actually ideal as your covering both sides of the light spectrum. That is if you can manage to keep the heat down and can pay the electric bill in full, on time, every time.

 

[jin420]

Using MH and HPS at the same time is actually ideal as your covering both sides of the light spectrum. That is if you can manage to keep the heat down and can pay the electric bill in full, on time, every time.

Yeah no problem paying the bill my rate is 9 cents/kwh and I usually only run the hps for 10 hrs a day. I live on the gulf coast and lately it's been getting cool enough at night that I've been able to shut the window ac off and pump air in from outside with a 6" centrifugal fan. With outside temps between around 65-70F I can keep up with the one hps and keep my temps around 82-86F. When the nighttime temps start dropping below 65F I can start running the mh too without the temps going above 86F. I have a thermometer that hangs between the two hids which are spaced 2ft apart and it sits at the same level as the lights. I figure it should be warmer where it is then at canopy level 8" below so having my temp reading there should ensure my girls aren't too hot I figure. With it where it is I imagine it's at least 2-4F cooler at canopy level so I'd think I'm fine. The room has a lot of air space in it and I have two box fans running on medium with the lights on. Then during the dark period only one box fan is on and it's on the low setting.

But I am only running the 400w mh when it's cool enough to shut off the window ac so I offset the cost of running it. They both use around 500 watts so the electrical cost is the same with either one on.

 

[Rj41]

I give full spectrum most of the way through flowering. I'm a firm believer that best indoor plant performance comes by best imitating the outdoors.