Cdub97
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I understand old school magnetic ballasts (typically for MH or HPS bulbs or convertible) work fine for CMH bulbs. True? Is a 400w sufficient? I understand I’d need a socket adapter if the cmh reflector socket set is mogul.
What size is your ballast ?
Most 400 watt bulbs, have a M59 ballast .
Well I have a couple. But they’re both digital. I’m not considering those.
I just considered picking up a secondhand unit. I’ve seen a few go in the $25-30 range so I figured if it worked
There’s a BUNCH of snake oil being peddled in the ceramic metal halide ballast world. Best I can tell they basically re-badged specific 315w ballasts and act like it’s some new tech. It’s not. The tech is in the gas mixture in the bulb. Some of these fancy cmh ballasts are overpriced old tech with a new product code...it’s kinda lame.
Best I can tell from reading people have had success using them. I think worst case scenario they’re slightly inefficient as the thing will pull a little more than it needs.
No
You need a square wave for cmh or very bad things will happen.
Lumens are for humans.
Par will take you far
Not in all cases, according to GE:
GE 400 Watt CMH Bulb Data Sheet
Specs:
• For use with 400w magnetic HPS ballasts
Those are not the new tech. They do not put out a similar spectrum or intensity.
The new base 315 cmh is the bulb that requires square wave. Which drastically increases its output over the old 400.
Sorry, you are wrong here. These are new tech CMH in a mogul based bulb. Yes, new. Not old school MH. They are not 'drastically' different. They are marginally different, by all of 2.4% better for the 315 CMH bulb over the 400w CMH bulb. If you do the math comparing the lumen output per watt, since you seem to like lumen comparisons so much. Actually the mogul based CMH bulb is a LOT brighter. 41k lumen vs. 33k lumen. The expected life span is the same. The color temps are the same range. The CRI is typically higher in 315w bulbs, a slight advantage, but that varies greatly between 315w bulbs. This information from GE, HTG and Phillips:
Specs from GE:
GE 400w CMH mogul based bulb
• 400 watts
• 41,000 lumens
• 20,000 hour lifetime
• 3,000K color temperature horizontal position
• 3600K color temperature vertical position
From HTG:
Ceramic metal halide (CMH) grow lights have developed quite a following in the indoor gardening industry. With a balanced spectrum and beneficial ultraviolet (UV), the output CMH bulb is closer to natural sunlight than any other type of HID grow light bulbs available. Our HTG Supply Value Series CMH system featuring the GE 400w ceramic metal halide bulb provides the bright white spectrum of a typical MH lamp combined with the powerful red spectrum of the HPS lamp for outstanding growth and excellent efficiency for outstanding growth and yields.
Typical 315w CMH bulb specs from Phillips:
- 315 watts
- 33,000 lumens
- 20,000 hour lifetime
- 3,000K-4,200k color temperature
I'll stick with my tried and prooven Philip's cmh and prism ballast and my dialed in setup.
Theres a reason why I like and only run Philip's 315cmh bulbs.
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You can get a new 400w MH mogul base bulb for all of $12 online now at 1000bulbs. Cheap as chips. If they last half as long, big woop. They are 7x cheaper than CMH. 400w HPS lights are about 40% brighter than MH, and 20% brighter than CMH. 50k lumens for HPS vs 36k lumens for MH, and 41k lumens for CMH in the 400w range. So old school HPS would be the biggest bang for the buck. Ligtht falls off at the inverse square of the distance from the source though, and so in reality, all indoor lights suck compared to the sun. Any indoor light. LED, HID, M-O-U-S-E. Simple physics.