par or lux meter?

a 6500k will have more PAR then a 10k .. and more then a 15k.. and more then a 20k..

so if you use the PAR to choose a light.. you automatically make the calculation on the PAR of that light-wave.. and then you have th lux..

so no direct link from par to lux.. they are linked in a formula with the light-wave..

different light wave with the same par gives different lux.. and different wave-light with same lux gives different par..

as we tested with a quantum meter in a university in italy tnx to a doc that was curious..
we tested 20 bulbs and we sa there were a link of the 3 but most depends on te lightwave..

some ligths have more luc (as our eyes can see..) bud had low par due to some light-frequecy missed in the lightwave..

so no.. they arent linked.. also if usually they are a step behind the colour and the lux..

but.. no.. not a direct link.. iwasaki were a 6500k .. one of the best wavelight for par as it's the best for photosintesis.. and will look yellow as you can see.. as much of the par is in the red and yellow..
so when yuo remove red and yellow in a bulb you loose much par.. so you need more power to reach the same par..

i want the same as yuo.. good looking tank.. so i dont care too much on the par as i know a 3x400W will give enough par also with 20k colour lights..

but the question was another :-D

 

that is not true. I was running 10K XM bulbs with Blueline E-ballast. Through reading Sanjay's web reference I discovered that 14K EVC Tech bulbs with my Ballast give highter PAR than the 10K XM's.
And I'm sure I could find a 10K that has less PAR than a 20K bulb based on Ballast/Bulb performance

J

 

Jason,
Also using the same reference that you quoted the 20K XM bulbs had a higher PAR or PPFD Value than the same manufacturer XM 15K bulbs

Jim

 

do i dare bring in CRI? or are we having to much fun with PAR and LUX

 

CRI is easy just a number to tells you how near a bulb wavelight is to the sun ligth at that kelvin temp..

nothing hard to check..

btw.. just for what Diver told.. we can understand that there is no direct relation between par and lux.. as some lamps with same lux but different lightwave can have different par..

par is related on how a wavelight can stimulate the photosintesis.. and lux is a part of the par formula ;D not just par = lux x constant

:

 

I agree, but do feel in general lower K=Higher Par: Saki vs. Radium The range of ballasts available just makes this generalization even more messy.

Keep in mind the Kelvin ratings we're given are near meaningless

 

Well I think about all here are painting this subject with a vary vary vary broad brush.. When I see a reference to My Ushio gives this and the Aqua-line do this and all Coral life are this .. You take 4 manufacturer's and test them all K for K and you will get 4 different readings . Hell take 4 bulb from a case and you will get a different reading.. Not to mention where on average your local power supplier is providing true voltage and amperage to the home or build is providing at a average level.. Hell test your own lights with your par meters at 3:00 am off peak and at oh say midday hot summer high peak tell me what you get.. Test your nearest wall receptacle and see how close to get to 120 V you get and if any of y'all own a amp meter tell me what the amperage is at the outlet This all varies from state to state and city to city country to country . All bulb's and Transformer manufacturer's not to mention Local Power companies are not equal.. Close is good and nothing in a living environment is never static and always changing.. Reef's get cloudy days anyone ever run a lighting track ??

 

this is why i told par -> lux arent linked directly ;D

btw.. the question of RG was if was better to buy a par meter or a lux..
and i told a par as the lux are written on the info of the bulb or easy to find in internet.. and par cant be calulated with the lux/lumen unless you have the info of the wavelight power graph and a program to make the par..

so a quantum-meter is cheaper and easier..

 

interesting results with such a simple question

 

: : ;D