JohnC
Member
Hi,
I'm in a discussion with a well know budget bulb supplier (i won't mention the name out of politeness) about some T5's i got the other day. They were noticeably dimmer to the naked eye so I decided to get my PAR meter out and do a little testing....
They are coming out 15% less PAR then my year old Arcadia Juwel type plant bulbs.
Since I was already thinking my Glosso is on the verge of wanting a bit more light in places and putting the reflectors on, the new bulbs were meant to keep it in the "happy range". Now i'm thinking the opposite. Light reduction and will need the reflectors.
So being slightly miffed I sent a polite email to said supplier and his reply with this -
Now obviously there is a mix of cut and paste stuff in there and fuzzy definitions of stuff as well as slipping into Lux chat in the second paragraph.
But this PUR thing got me researching before answering back. (the bulbs are cheap and even show a 10% difference in output between them).
The planted tank forum has some good discussions between Tom and others.... The gist of which is that there hasn't really been any/much work done into different PUR needed for the 300 - 400 species of aquatic plant. Where in the Marine world there has been work done on this front.
http://www.plantedtank.net/forums/showthread.php?t=78632
http://www.plantedtank.net/forums/showthread.php?t=136341
So my question is -
I'm aware PUR is being pushed by the LED manufacturers and marine world but is it just "fuzzy science" currently?
Has there been enough new research into PUR in tropical plants since Tom Barr made these posts for a cheap bulb seller to feed me these lines? or am I just being fobbed off with some science chat like I feel i'm being?
Oddly I do have the perfect test to see since my glosso was on the edge of not enough light in my opinion. If it grows up now I will know.
Opinions specifically on new information not covered in the planted tank thread please. The discussion there is already quite in depth (thanks to Tom and the other contributors a few years ago).
Best Regards,
John
I'm in a discussion with a well know budget bulb supplier (i won't mention the name out of politeness) about some T5's i got the other day. They were noticeably dimmer to the naked eye so I decided to get my PAR meter out and do a little testing....
They are coming out 15% less PAR then my year old Arcadia Juwel type plant bulbs.
Since I was already thinking my Glosso is on the verge of wanting a bit more light in places and putting the reflectors on, the new bulbs were meant to keep it in the "happy range". Now i'm thinking the opposite. Light reduction and will need the reflectors.
So being slightly miffed I sent a polite email to said supplier and his reply with this -
"Hi John,
Thanks for your email. I’m sure you already know that the PAR of a tube isn’t necessarily the most important measurement to take, here at ******* when we develop a tube we look much further than PAR. A high PAR reading doesn’t necessarily mean a better bulb, we try to use PUR (Photosynthetic usable radiation) as our base line as this is the part of PAR that is usable by plants and corals for photosynthesis. If I can give you the example of a standard household fluorescent, it has an incredibly high PAR reading as it is designed to be “bright” to the human eye, out of that PAR there is very little PUR.
The human eye response only sees light in certain parts of the spectrum which is why we try not to use the term “bright” when talking about our tubes as we design them to be beneficial to aquatic life, not to look “bright” to the human eye because as we have already mentioned most of the light we see as humans is completely useless when it comes to photosynthetic animals and plants.
Please find below a few links to articles we have put together that explains this in a little more detail, if you would like to discuss things further please do not hesitate to give me a call for a chat."
Now obviously there is a mix of cut and paste stuff in there and fuzzy definitions of stuff as well as slipping into Lux chat in the second paragraph.
But this PUR thing got me researching before answering back. (the bulbs are cheap and even show a 10% difference in output between them).
The planted tank forum has some good discussions between Tom and others.... The gist of which is that there hasn't really been any/much work done into different PUR needed for the 300 - 400 species of aquatic plant. Where in the Marine world there has been work done on this front.
http://www.plantedtank.net/forums/showthread.php?t=78632
http://www.plantedtank.net/forums/showthread.php?t=136341
So my question is -
I'm aware PUR is being pushed by the LED manufacturers and marine world but is it just "fuzzy science" currently?
Has there been enough new research into PUR in tropical plants since Tom Barr made these posts for a cheap bulb seller to feed me these lines? or am I just being fobbed off with some science chat like I feel i'm being?
Oddly I do have the perfect test to see since my glosso was on the edge of not enough light in my opinion. If it grows up now I will know.
Opinions specifically on new information not covered in the planted tank thread please. The discussion there is already quite in depth (thanks to Tom and the other contributors a few years ago).
Best Regards,
John