The Grim Reefer said:
One thing to keep in mind is a cheap PAR meter is no solution for a good spectrometer(learning more about this crap than Iever thought I need to just to have a fancy fish tank). Fluorescent lamps have a more spikey output than halides. Having an equal amount of PAR the halides would likely provide a better quality of light to the corals, closer to natural lighting. If I can't at least match the PAR using the halides the T5 are going back on.
I would love to see one of the guys with all the expensive equipment do some real world tests instead of all these steralized lab type experiments. Do the measurments with an established tank with rock in it.
Grim,
1. If I ever get around to it I'll try get into more detailed discussion of PAR readings, but "sterilized" tests give you a accurate/repeatable base line guide. It would seem to me that 'real world' tests can be more misleading as there are too many variables that cannot be reproduced each time you do a reading. So then you get misinterpretations of the value of such data. Take your tests so far; with differing distances from the light source, different ages on the HID or fluoro, and unknown wattages the tubes are actually running at. Actually, I from my limited understanding on fluro's they are current limited for a given (assuming constant voltage ) given ballast, and as such the actual wattage a T5 or T6 is being driven to, would depend on both the tube design (thicker filament will allow for higher currents in overdrive, or longer lifespans) and ballast design. Unfortunately IceCap merely states 110w per channel for stats on their ballast, whereas the Workhorse will state maximum current their ballasts will deliver.
2. Was it Yu L LI who stated on another thread(see reference links below) there was a way to measure current that the individual tubes are being driven at, from which you could make a reasonable estimate of the wattage? In other words you have IceCap stating a 4ft 54w T5 tube is overdriven to 80w when used on a single 'channel'/lamp setting of the IceCap 660. So, even considering ballast losses as you would get with 110wVHO's which would run slightly less than 110w per channel, we see that the T5's are likely limited by some factor like the filament diameter/wire gauge, as the ballast should be able to provide enough current to run them at 110w. Now depending on how the T6's that Yu L LI sent you are designed, you might be able to run them with 2 sets/channels of leads connected to just one T6? Perhaps you have already discussed this with Yu L LI? But I suspect the 660 ballast is limited to somewhere around 1.5amps per channel that a VHO tube would draw at spec'd ratings. Doubling up on the leads to one tube I expect you'll run into overdrive limitations like the T5 with those T6's (but perhaps not as much). But it would be nice to measure the amount of overdrive you could get with 2 leads driving the one 145w T6...to what 200+w?
3. Guess I'd better do another search on PAR measurement taking, various types of sensors; but still a 1000wHID is going to give higher PAR values assuming you have someway to vent the extreme heat output
. However, when comparing all of these different light sources, one should also keep in mind the luminous efficiency (is there a analogous measure of PAR efficiency?) or lumens/watt. Total amount of heat generated will partly depend on how efficient the light source is. HID's are typically at 100lm/w or higher---but due to the manner of light production, produce plasma balls that generate lotsa, lotsa heat :smokin: , HPS horticultural lamps being even more efficient and typically having better PAR spectrum outputs. Of course it would be nice if all manufacturers would publish PAR data, as a T5, T6, or HID of same wattage and same 100lm/w efficiency could have significantly differing PAR measures. HID's be nature of being a 'point source' (the plasma arc ball) of light will likely succeed in best PAR values per given wattage at greater distances from the light source. However, given sufficiently high enough output wattages of fluoros you may be able to get close to same penetration depths with more uniform coverage than an single or dual HID setup. Just a theory on my part, but more uniform coverage may promote healthier growth. You would need to do extensive testing to prove that theory.
4. So do we have PAR measurements on the T6's yet, and could you change the title of the thread to make note of T6, and HID comparisons (or maybe start a new thread?)? Can you include the tests with the new reflector Yu L LI thinks is a good choice, do you have these yet, or are they coming soon? And BTW, only one set of T6's in your possession, what about the 90w HO T6 48in or shorter lenghts for those looking to keep the heat levels lower, less cooling required? I suspect, that while Yu L LI is correct that driven to spec'd wattages they will easily be much brighter in terms of both visual lumens output and PAR levels, you would expect that even in an overdriven 80wT5 vs 90wT6 configuration. But T5's are designed for optimal lumens output at, if I recall, somewhere around 140C? So then a 90wHO T6, while perhaps having the same lm/w efficiency, might exhibit lower overall temperatures due to the slightly larger diameter tube design...???
5. Some links to other forums or threads you are referencing would be handy for many, example Sanjay Joshi's(sp?) site? TIA
6. Always helps to have an inordinately understanding SO, when you get mired/tangled in the forest/jugle of adult toys/hobbies? ;-)
T6 Reference threads:
T5 lights, how long to they last and what's the equivalent watts produced?
T6 Lighting for Aquariums
Sorry, but I don't spend all my time online; I find it nearly impossible to keep up with the sometimes 10 new pages of threads that pop up on this forum alone
Gads you must REALLY love your lights now!! Good thing you wern't running Ice Cap ballasts, The plastic might have melted into the metal. I've heard of a few people doing that with new halide reflectors.
