I went through the first page. No Insult to Him but he is Talking about Metal Halide lights . An old subject , are they even available ? I would guess that led was in its infancy at the time. One though explicitly told someone to buy an Apogee 510. As to lux meters I have one cost me $125 . Just so everyone understands an Apogee cost me $ 1200 . I certainly don't see how anyone can compare them. I did not research very far into a Lux meter study . I stopped when I read they are inaccurate , and favor blue , and green , and are of very little value for anything else . I can only assume because of a superior sensor . Lux meters are for plant growers , and deal in the visible light spectrum. To me they don't have to compensate for the variables that I should not have to explain when used in an Aquarium environment. A lux meter only deals it Air. I don't count on absolute accuracy from a Par meter and I don't care . As you are probably aware Par does not have to be a finite number ( which by the way I read dozens of articles , and read the same regarding a Par meter. I am not one to just spend money needlessly. ) Back to use Coral don't need an absolute like I said as you know. I also use my eyes as suggested by Bean Animal . Its interesting to me to see how Par fluctuates when using wave makers , which make them useless and possibly why people blame the par meter and not the set up. Also seeing the effect of lids on the intensity is valuable to me. At least they hopefully eliminate light as the problem , so you can look else where for the issue / issues that exist. I happen to think Parameters are a rabbit hole. I Unlike some I try to make sure People know that I am not a scientist in any field. I have a real hard time excepting statements from those that don't. They are a tool like any tool the user has to be competent which I strive to do. This is meant to help the original person to make a choice by reading both sides of a " Discussion ". Not meant for two people to argue . That is also my Goal. I see lots of People who have the attitude that if someone disagrees with them then they are obviously uneducated , and Ignorant . I again don't care if anyone disagrees with me as long as its helpful to those that are asking advice , or direction
