Is it safe?

[Barney86]

Hi folks here's my situation.
I've got my seedlings rooted up but my main space is still too busy for them.
Need to give them some more juice as my seedling light needs replaced.
I've got a 130w ballast and a 600w CMH bulb. Is it safe to put the big bulb in?

 

[Weaselcracker]

I don’t use CMH Barney, but if you’re asking what I think you are. A 600 watt bulb in a 130 watt ballast (assuming it fits) will still use only 130 watts. It shouldn’t be dangerous in any way, but at best the bulb will not be running efficiently at all and will be quite inferior to using a 130w bulb in that ballast. At worst it won’t light up.

 

[LiberalThinker]

I would not do it. CMH is nothing like HPS or MH. It is its own technology with different electrical requirements.

 

[Barney86]

I don’t use CMH Barney, but if you’re asking what I think you are. A 600 watt bulb in a 130 watt ballast (assuming it fits) will still use only 130 watts. It shouldn’t be dangerous in any way, but at best the bulb will not be running efficiently at all and will be quite inferior to using a 130w bulb in that ballast. At worst it won’t light up.

My thinking mate, is that I got the 600w bulb with a 600w dimmable ballast that goes down to 200w. So, my version of logic says that this should be safe.
And also that you are correct in that it would just run my 600w at 130w. And that's all I want. The bulb it's replacing is a 130w CFL that came with the reflector .
It's the same size Bulb as any other light, HPS CMH, just that it's a cfl. and it's the same fitting.
I've tried it and it works.
Just need to know if it's safe?
It's in my walk in wardrobe so can't just leave it on to check it. Melt my house in an hour lol.

 

[Barney86]

The CFL has done around 18months now. It's fucked lol.

 

[Weaselcracker]

I can’t say for certain, since I don’t know much about CMH and maybe they have something different in their design that would prohibit dimming as YellowBelly implied. It’s hard to find real info on the subject especially from canna-forums where you usually get a bunch of random opinions including the Chicken Little stuff about how you’re an idiot and going to blow yourself up.
Generally speaking, dimming a bulb causes it to operate inefficiently, and the more you dim it the more inefficient it is. So assuming it works otherwise, it will use 130 watts but not give you anywhere near 130w worth of lighting. Also the dimming tends to shift the light spectrum so you’re losing quality of light on that front as well.
I emailed Hortilux at one point to ask them about the subject of dimming HPS and HID bulbs and that’s basically what they told me- avoid dimming if possible because of the spectrum shift and the reduced efficiency.
I do dim the light in my veg room all the time when I want things to have less light. I don’t mind if it’s less efficient - I’m trying to dim it, after all.

I’ve also used larger than specified HID bulbs in ballasts a lot and have no problems to report. I used to commonly use 1000w HPS bulbs in place of 600s- because they are larger and cover a larger footprint. I stopped doing that after the Hortilux guys told me I was losing efficiency that way.


I think if you want a proper answer for your specific scenario you’d get the best results by emailing the manufacturer or other lighting experts. Post results here if you do!

Of course one way to do it is to just go ahead and do it and see what happens and if the plants grow. Report back if you live.

 

[Weaselcracker]

For what it’s worth here’s that email I mentioned. Not specific to CMH of course


“Great question and you are correct. There does seem to be a lot of misinformation about this.

One message we at EYE HORTILUX have never strayed from is that you should never dim your grow lamps. You will not be getting what you paid for. The spectrum is affected and lamp life can be reduced. We recommend that if you are trying to reduce power usage or heat, that you purchase a lower wattage system and run it at 100%.

Of course, there is an exception to every rule. Now, the issue here is the difference on how the spectrum is affected for an HPS or Metal Halide.

If you are dimming a High Pressure Sodium lamp, then the spectrum will not be as intense as the spectrum you bought. It will also eventually lose the blues when dimmed too low. And can affect the lifespan of the lamp. (I was told dimming a 1000W to 600W is not too bad, but that should be the limit)

If you are dimming a Metal Halide lamp, especially a HORTILUX BLUE, you will experience a complete spectrum shift. The chemicals will react differently than they are designed to and the continual dimming will lead to premature lamp failure.

Overdriving as much as 10% doesn’t seem to be much of an issue. You may see very little spectrum shift but may see lower lifespan of the lamp.

My in-depth source is the scientists and technicians we have here at our manufacturing plant. Wish I could help on outside authorities.

Hope all this helps.

Happy growing!”

 

[Barney86]

I can’t say for certain, since I don’t know much about CMH and maybe they have something different in their design that would prohibit dimming as YellowBelly implied. It’s hard to find real info on the subject especially from canna-forums where you usually get a bunch of random opinions including the Chicken Little stuff about how you’re an idiot and going to blow yourself up.
Generally speaking, dimming a bulb causes it to operate inefficiently, and the more you dim it the more inefficient it is. So assuming it works otherwise, it will use 130 watts but not give you anywhere near 130w worth of lighting. Also the dimming tends to shift the light spectrum so you’re losing quality of light on that front as well.
I emailed Hortilux at one point to ask them about the subject of dimming HPS and HID bulbs and that’s basically what they told me- avoid dimming if possible because of the spectrum shift and the reduced efficiency.
I do dim the light in my veg room all the time when I want things to have less light. I don’t mind if it’s less efficient - I’m trying to dim it, after all.

I’ve also used larger than specified HID bulbs in ballasts a lot and have no problems to report. I used to commonly use 1000w HPS bulbs in place of 600s- because they are larger and cover a larger footprint. I stopped doing that after the Hortilux guys told me I was losing efficiency that way.


I think if you want a proper answer for your specific scenario you’d get the best results by emailing the manufacturer or other lighting experts. Post results here if you do!

Of course way to do it is to just go ahead and do it and see what happens and if the plants grow. Report back if you live.

Thanks for taking the time there mate I appreciate
I certainly won't be asking any light companies about anything though.
I'll take your word long before I listen to any of them. Hence why I asked.
Golden rule of growing. Don't listen to anyone that stands to make money from you. Always ask a grower first.

That's exactly what I wanted to hear though funilly enough. I'm not bothered about it not running at full capacity, it's only got to replace a 130cfl that's done about 18 months on 18/6. Does surprisingly well though... Fuck it hang on .........

 

[Barney86]

Check it lol.
They look good but almost 4 weeks old now. I'm not in any hurry, got a few weeks before my bloom space is ready as I'll need to give them a couple weeks veg in whatever media they end up in before I flip.
That's a 14000k 130w CFL bulb I use specifically so the plants focus on the roots. They always stay small to start with but they're usually that size by day 17. Prety dissapointed with the roots too.
I'm off work tomorrow so I'll try the 600w CMH bulb and see what happens.
My leccy breaker is sound so at least I don't need to worry about anything else blowing lol

 

[Weaselcracker]

Good luck!