malulu said:this is the light i have... been using it since Feb 2005, there are 3 HQI.
http://www.aquarium-supply.biz/products/CoralifePro72LG.jpg
my plan for going forward is every 3 months i will change 1 HQI, so the ussage of each HQI is about 9 months. (last time i changed was on Sept 2005, the 2nd one will be on Dec 2005, then 3rd one will be on Mar 2006...etc.)
thx for reply...