I replaced my existing tubes exactly 9 months and 10 days ago. My tubes arrived last week from Germany in one piece.
I have just taken PAR measurements using an Apogee Quantum sensor connected to a multi-meter (readings are multiplied by 5 to obtain mmol values). I have run my 8 tubes for 9 hours before taking measurement. Water was very slightly turbid due to water change a few hours ago. Furthermore, there is no GAC filtering. Here are my readings:
These readings look OK to me. Because coloration of my corals are constantly improving and growth is rampant, I cannot justify tube replacement.
Do you, the SPS boffins, agree?
Cheers
Bulent
PS. Coral fragments on sand bed are going to my lfs on Friday. They will partly finance the purchase of a Genicanthus Watanabei.