Such a crock of shit man....I know this is B.s.. If you have a light meter you will be able to do this litte test. I have a Mh bulb thats 110,000 lumens intial and 90,000 mean. With the glass in and a 450 cfm vortex fan i have 85,000 lumens at my plant tops. Less than a 5% drop from the actual lumens. Take your meter and measure the light intensity at the tops of your plants with the glass and fan on. Now measure again with the fan and glass off. You will notice less than a 10% decrease. If glass really reduced your lumens that much then manufactures would stop selling them..
LOL not true bro its a fact that glass due to its crystalline lattice structure refracts and distorts light intensity by 10% (depending on its thickness) . Add fingerprints or dust to your lights and its even worse. If you know the principle of how hid bulbs burn you would know that the lumen output is directly proportional to the intensity of the bulb is based on the temperature of the air you are cooling your lights with and the temperature of the gas burning. As too your light meter I doubt it exists, otherwise you wouldn't be using a metal halide bulb if you were that into your grow technicalities. As to the comment about manufacturer's stop selling them there are other practical applications for air cooled lights like if you cannot afford an ac or are having excessive heat issues.
True i was thinking about that after i posted about that but didnt want to go back and edit my posts. I took my glass off and i got more than i ever did. The point is if you plants are that close to the glass they are going to block the light from the surrounding plants anyway. If you raise up your lights and take off the glass you get the same lumen intensity with more coverage and the same temperatures. Basically the most efficient way to use point source lighting.The heat you feel is also from light intensity (sorta), lol sometimes i think i can feel how many lumens im feeling because ive used hps for so long and know what feels perfect to the touch to use.Isn't indoor lighting from converted electrical energy, that is turned into light and heat energy? so is it fair to say you can judge light intensity if you know or feel the heat intensity?
That's if you don't want to talk about vert bare bulb
Yes sure no problem. A metal halide bulb is 10 % less efficient than a HPS bulb in terms of light intensity and power consumption. MH bulbs are typically used in veg because they have higher lumen output in the blue spectrum than metal halide bulbs and help slow vertical growth and create shorter stockier and sturdier stems that are able to support more flower weight. ( This is an outdated method of thinking due to new technology). Also, MH bulbs give off more uv light that is believe to increase THC content by many. Typically 15% of the energy that is used by MH lamps is emitted as PAR as to 13% for HPS but the white light emitted by the MH bulbs lacks in the red spectrum intensity that is necessary for flower development and photosynthesis. They are good when the amber light of a HPS bulb would blow up your spot while a MH bulb is less recognizable as a grow op with its white light output. To get the benefits of MH and HPS bulbs together i use a HPS bulb that has an added blue spectrum to balance out the red spectrum to keep the plant from stretching too much. Then during the last two weeks of flowering switch in my MH bulbs to drastically increase my THC content.
Are you unfamilar with burn-in?
Yea also a good point to bring up when using HID lighting. That contributes to why I change my bulbs every harvest. By the time you use them your not getting the exact lumen output that manufactures claim and using them reduces the intensity of the bulb dramatically in just 2 months of use.
I am just noticing this, harvest dramatically increased now that I use new bulbs every run, I use to burn HPS bulbs for like a year b4 I'd replace
Nice yea the temps are gonna be your only issue. To combat this think about air movement in the grow room with oscillating fans, the heights of the lights, air removal from the top of the grow room, adding ac, reducing your ballast dimmer switch, and Air removal/renewal in your room.