well your not over looking it, i can say that much. the site doesn't list the exact
K rating, since the bulbs are meant for plant lighting, and term 'suitable for general plant growth' or 'suitable for the flowering/fruit period' is enough to sell the product.
5k - 6500 is suitable for general growth, and anything lower than 5k is considered a red bulb, and meant to be used during the flowering/fruiting period, to stagger growth of leaves and roots and force the plant to put that energy to fruit production.
what the site does list is where the bulbs have their peak output in the light spectrum. 5k-6500 falls into the blue, green, and violet specturm so the listing of the bulb will state that. like this one -
http://www.insidesun.com/index.php?action=item&id=157&prevaction=category&previd=6&prevstart=0
i do realize this can be a bit of a gamble but lighting requirements for plants (above and below water) and coral don't differ that much (expect the demanded use of actinics) but for the few people that will go the
MH way this is very cheap alternitive and will achieve very similiar results.
i understand all to well how effecienty works, and power out over power in, heat is wasted power, etc. and no light source is 100% effecient, leds are the closest at 98% of engery in, is made into light, and when they start rolling out Full spectrum leds in the next 3-10yrs look out as they are going to replace everything on the market today geared toward aquarium lighting. however HPS bulbs do get warm, warm enough to stop you from touching them while in operation, but not as hot as a regular light bulb, or
MH. the actual fixture i have in my backyard is made completely of plastic if that tells you anything. Mercury Vapor runs cooler than HPS lamps but they do cost a little more to operate annualry, i beleive its about a 4dollar increase (yearly) (i have a 250watt MV floodlight hanging over my garage).
well at 75bucks for a complete system (bulb included) that should last well over 3yrs without any color indexing problems its tough to turn down, you do get more wattage than a WH7, and it only uses 1 bulb, replacement bulbs run about 40-60 bucks, but they do last for the minimium of 3yrs (probably much longer) with the regular florescent bulbs you will have to replace them every 8-12months.
Mathmatical conslusion-
if you use 4 bulbs and daylight bulbs at my local HomeDepot run 7+ a bulb, and replace them once a year, that will be 28bucks.
in 3yrs it will be 84 bucks.
if the HPS bulb runs 60 bucks, 84-60 = 24 dollar savings,
lets say endcaps are 3bucks a peice 3 x 8(number of needed caps) = 24
40bucks (WH7) + 24(caps) +28(bulbs) = 92bucks
total price to get into a HPS system today 75bucks.
and you will save 24 every 3 yrs, plus the difference in annual running costs.
i don't know if its better for you to make the switch or not since the wattage of both systems is close, but using math you will pay more to keep a florescent system running over an HPS. only bad thing is having to find bulbs locally but 1 bulb = 250watts, just as powerful as
MH systems but cheaper.
i am probably going to go with ODNO if i can find a cheap elec. ballast or HPS system, when it comes time to worry about lighting,
still no word on my book yet, arg! 3rd party sellers on amazon, i will never do that again.
