thanx. i actually got the nova pro about a year ago, once i got into sps. the growth has been great. all the sps have pretty much tripled or more in size. i'd changed out the bulbs after 3-5 months to gieseman, uvi or ati. the clams r all doing great. the derasa is at the bottom more than 2 feet way and growing. i change water once a week aof bout 10%. the only thing i dose r calcium and alk buffer.