Is there a reason for six month?

[jsb]

Is there a particular reason to replace bulbs for PCs every 6 to 8 months? I've read replace them before the burn out, but what about intensity? Do they fade or get less bright as they age. I've got a PC setup and I'm on my 8th month of use. They're on for about 9 hours a day. Could I buy a replacement set, and wait until they burn out, or should they be replaced before hand for a particular reason. I'm asking because I've noticed my GSP is not looking a full as normal. I wondered if it was from light or water quality. I haven't been on top of my quality for a while now. I haven't tested in probably 4 months except for alk/cal, due to using Oceanic salt. BTW, the tank will be up for 2 years this Nov.

 

[marvida]

Yes, basicaly what you said. The more hours the tubes have on them the more the spectrum shifts. I change my bulbs once per year, probably a month or so too long. It goes by hours burned, not time so if you burn your lights 12 hours per day they will need to be replaced before a set that is burned 8 hours per day.

 

[jsb]

Thanks!