<a href=showthread.php?s=&postid=10057833#post10057833 target=_blank>Originally posted</a> by Yinger
alright... i was going to stay out of the whole light argument, but I guess I might as well say something. Mope, you mentioned that 2x65 watt pc's over 20 gallon is plenty of light, are you assuming that because your using the old adage of the watts per gallon rule? With halides, that's typically not what you want to shoot for. The intensity and what a light can produce is par of ppfd according to sanjay's site. With my old XMs on my ice cap ballasts, my pffd was around 115 which is enough light for any sps at any level in my tank. With the reeflux, my par of pffd is 86 which is slightly less but still enough. Now with the samoensis, it is an extremely light hungry coral along with any other species of finger coral.
Now with regarding Rykwong's lighting. The iwasaki is by far the highest performing 175 15k bulb out there. With eballasts, the output of the light is 86-89 pffd which is the same as my 250s and even quite a bit more than some other 250 14ks and 20ks. Now granted it's not as strong as XMs 10ks, but then again, his is a 15k bulb and 86 pffd is extremely intense... especially for a 175. So your statement of 175s being not as intense is not true.