I suspect that you have a borderline deficiency of calcium & magnesium. Plants grow faster & take up nutrients at a higher rate with more light. Going back to HPS puts that uptake back into the range of what's available.
purplepassion
Member
I hear the de versions put out a lot of radiation. Stick to single ended cmh.
dat130ysmurf
New member
so feeding increased nute dosage should be the solution?
Or maybe just add cal-mag or similar to the nutrient solution. I'm not a hydro grower so I'm not a good source of advice on the subject.
What I like about the single ended 630 CMG, is, you run 2 lamps so you can mix spectrums. Im running 3000K Reds, and 4000K blues in each fixture
I like the redundancy of twin 315's in my 4x4 space. If one ballast fails the other keeps working. When the capacitor failed on my previous 1000w mag ballast I had to rig up other lighting to maintain photoperiod & fix it right away, actually the same day. PITA. The way it is now gives me more time to deal with a failure.
Which reminds me that I'm still looking for a great deal on a philips or similar ballast as a spare...
Dunno about that particular comparison (it's kinda vague) but more PAR means hungrier plants in general. I'm sure there's some point of diminished returns where more light isn't worth the money to create it but I don't know where that is.
CMH= more PAR per watt. A lot cheaper to run a 630 for the same bang as a 1000 watt sodium.
Your electric bill will be 37% cheaper
CMH= more PAR per watt. A lot cheaper to run a 630 for the same bang as a 1000 watt sodium.
Your electric bill will be 37% cheaper
I really didn't notice any change in yield when I went from 1000w to 630w of CDM's.
As you say, the electric bill is considerably less. There's also proportionately less total heat to dissipate. I had trouble keeping temps right in hot weather using 1000w but it's easy now, even turning down the fans somewhat. If you run A/C then electric savings there will be proportional, I think. There may be better answers for larger grows but twin 315's in a 4x4 is near ideal for us.
The price & availability of 120v ballasts makes them very attractive for anybody willing to put a little more up front, particularly anybody who has high electric rates. They'll pay for themselves over the first few grows & then it's just more money that stays in your pocket.
I think the high price of genuine philips lamps is offset by their much longer life so that's pretty much a wash. If I replace a 1000w lamp once a year, that's $75. If I replace two philips lamps every two years, that's $75/ year. Same-same.
Nirrity
Active member
so, is there any consensus in what color temperature is better overall: 3000K or 4200K? Also, does higher CRI have any beneficial effects over lower 80 CRI?
looking at this chart (if it's accurate) i'd say 4200 is better since it has more spikey red around 650 nm, less pronounced yellow/orange and more blue, while 3000K has huge spike around 680, more orange and less blue. i may be mistaken but 680 isn't that good at all, is it? seems closer to IR than usable light.
looking at this chart (if it's accurate) i'd say 4200 is better since it has more spikey red around 650 nm, less pronounced yellow/orange and more blue, while 3000K has huge spike around 680, more orange and less blue. i may be mistaken but 680 isn't that good at all, is it? seems closer to IR than usable light.
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digging
Member
In regards to colour temperature, most people are using the 3000 for flowering, and the 4200 for vegging.
Having said that on CMH fixtures that have two bulbs some people in flowering are using one of each bulb to get a varied spectrum in flowering.
In regards to the CRI indexing, the higher the number the closer the light spectrum is to the sun. The sun would be at 100.
Most CMH lights I see are anywhere from 91 to 96.
Having said that on CMH fixtures that have two bulbs some people in flowering are using one of each bulb to get a varied spectrum in flowering.
In regards to the CRI indexing, the higher the number the closer the light spectrum is to the sun. The sun would be at 100.
Most CMH lights I see are anywhere from 91 to 96.
Dunno about consensus but I figure Philips did their homework in creating the 930 agro lamp for horticulture. They have scientists. I'm just some guy who grows his own weed...
Any of their 315 lamps is a great choice. I'll stick with their lamps, in part because they appear to have twice the rated life of the competitors but don't cost twice as much...
Using CRI in horticulture industry is a mistake. CRI is a scale of 0-100, it is used to describe how accurate a light source renders color of an object.The higher the CRI, the better the color rendering ability. Plants don't need high CRI light to render their color.
The most important criteria is SPD, then the relative strength of different wavelength lights, the last is PPF.
Philips 3000K and 4000K bulbs are full spectrum, both can be used for veg and flower. If you have a 400W dimming CMH ballast, better to use 4000K bulb.
https://www.facebook.com/SunPlix/ph...894316928263/2055876931096660/?type=3&theater
Is this
BaddAss Low Frequency Ballast 1000w
Compatible with this
Philips 421784 - CDM860/V/O/4K/BT37 EA
BaddAss Low Frequency Ballast 1000w
Compatible with this
Philips 421784 - CDM860/V/O/4K/BT37 EA
Are you saying better growth with high cri in leds?
They're all excellent. OTOH, I have to respect the scientists at Philips who developed the 930 agro lamp. I figure it's the best of the bunch for plants or they wouldn't bother making it-
http://boulderlamp.com/315w-agro/
