[jcltok]

Can you give me the reference information so I can find Dana Riddles research. Thanks I appreciate it!

You state: "As for the exact light output your home reef gets... it all depends on what you want to keep and how tall your tank is. The light levels at the bottom of a tall tank with 400 watt halides could be replicated by a 108 watts of T5s over a 10" tall frag tank. The light at the surface of the tall tank might be 700-900, and at the top of the frag tank, only 300... but in both cases, where the coral is at can still be 200. Thats why I found your suggestions ill-advised.

Hahnmeister - what suggestion? One suggestion I made to another poster on another thread about how much PAR to aim for was based on the work of John Ryther from the Woods Hole Oceanogrphic Institute. Is that the thread you are referring to?

By the way, what is the PAR of 108 watts of T5s (brand please and model number) at what distance from the water? I am sure everyone will appreciate that information!

You state: "The other thing to keep in mind (not aiming this at you) is that our home aquaria are usually constant intensity over the course of the day. So calculating MegaMol/m2/day is what you have to do when comparing to nature. A constant intensity of 700 over 8 hours might equal the varying intensity that peaks at 2000 over the course of 11 hours. Comparing corals to what they get in nature seems to be a futile thing though... photosynthesis is all about a balanced chemical equasion. Due to lack of phytoplankton, flow, and other things... this rate will not be similar to what is in nature, so trying to match the light output isnt always the best thing either."


PAR is not cumulative. PAR is how much light is reaching the coral at this moment in the span of one second per square meter. The light is there or not there. So, why is measuring MegaMol/m2/day useful - I do not understand?

Regards,