What is T5VHO vs T5HO?

[banditpowdercoat]

I'm really curious as to how you can say T5's last 2+ years with no appreciable PAR loss when many have tested, all independently, I may add. And those tests say that after 10 month's, T5's can loose 40% or more of their PAR. My bulbs are a year old, 12 hrs a day on time. And I notice a diminish in light output. I can look at the lights when on now. No way I could look at them when they were new.

[Binare]

For starters, PAR (Photosynthetically active radiation) has nothing to do with "bulb output". PAR is a range of light, exists between 400 & 700 nanometers, light used by photo synthetic organisms... also about the range humans see. A PAR meter measures whats in that range, has NOTHING to do with brightness. LUX, a unit of measurement coming from Lumens, THAT is the measurement for brightness.

Don't confuse PAR with LUX, comparing apples to oranges. I do not use rebranded reef bulbs that cost an arm and a leg compared to the ones produced by major manufacturers (such as GE, Phillips etc) who at best guess from me produce thousands upon thousands of times the amount of bulbs the entire aquarium industry sells in total. They say there bulbs last x amount of hours, and I say of all the bulbs I have used from them have shown me on average about the same performance.

The only exception is Actinics, thats my current bain needing to buy those damn things.

I'd really like to see one of those "independant studies", maybe post a couple, Ive searched and searched before I posted and could not find a single lab quality or even remotely professionally developed research panel conducting any sort of study that would cause an entire lighting industry (worth billions) to hold its breath. Or are you referring to the "homebrewed" studies done in ones own living room with a cheap consumer purchased PAR meter used by someone who more then likely doesn't understand fully how to use it... no offense to anyone, explained to people who don't fully understand PAR? Trust me.... I don't fully understand how photons of different wavelengths create a visually perceptive difference in light. You also won't very many scientists who agree on how to measure PAR and how those devices react to artificial light opposed to natural (the sun).

Like I've said before, take it with a grain salt, trust the company who sold the bulbs and not the ones who research and designed them, makes no difference to me. I'm lucky in that I have access to a proper PAR, and LUX meter... and all the help and advice I need from some the worlds best industry reps when it comes to lighting.

On a side note, eyes are poor for judging PAR and LUX, eyes adjust long and short term to different wavelengths, do you remember the first time you looked at an Actinic bulb? Is it the same experience at looking a brand new years later? Taking the bulbs and cleaning them off along with the reflector as scheduled maintenance on the tank helps to, I do mine once a week with water changes.

[Binare]

Just for arguments sake, the PAR meter I have used is actually a spectroradiometer, not a consumer grade off the shelf 65.00 Milwaukee handheld unit.

[StirCrazy]

Originally Posted by Binare

The only exception is Actinics, thats my current bain needing to buy those damn things.

um. actinics are the simplest bulbs to get in a major brand,, Phillips created the actinic bulbs for photocopiers. look for a Phillips 03.

PAR is not a complicated thing, don't make it into one. Yes it decreases as a bulb ages, and no you don't need a spectrometer to know if it decreases or not.

I never know Milwaukee made PAR meters, and the only decrepency in how to measure it are which units are the proper ones to use.. it is measured the same either way.

as for lumin, they are pretty much a usesless measurment to us I do own a PAR Meter ( And yes I do know how to use it) and have done long time tracking of PAR decrease in bulbs, while it is n't as much as one would thing there is a decrease over time.

Steve