Changing PC Bulbs - How often?

[ElMonoCalvo]

I have a 12 gal Nano with the 2 stock 18w 50/50 PC bulbs that has been up and running for about 6 months now. My previous tank had VHO lighting which I switched out every 6 months. Do I continue the 6 month routine or can I go a little longer with this type of lighting?

 

[Anonymous]

I think I've read that PC bulbs typically fade at around 9 months so sticking with 6 months should be safe. - Depends on what you're keeping though really.. - If its all really low light stuff you might feasibly get by without ever changing them. - If you have high light demanding livestock you'd want to make sure you kept up on it.

If you have an LFS or local club with a PAR meter you could check every so often and see.

 

[ElMonoCalvo]

Thanks for the input GratefulDiver.

I've got good corralline algae growth and a small cluster of polyps and xenia that were recently added seem to be doing well under the current bulbs. The plan now is to swap out one of the two bulbs every six months.

 

[Anonymous]

FWIW, I've got some xenia "colonies" that are coming back after having been nuked by a large extended temp spike. (Office went up into the upper 90's over a long weekend..) - They're coming back while under a singe 36w 50/50 thats about...... 4 yrs old.

I also have 2 small heads of green candy cane coral (Caulastrea) that managed to survive that are doing fine under these old bulbs too.

Oh, and if by "polyps" you mean zoanthids, no worries there either. You can probably get by without swapping and save your $$ for more frags instead.

Check this out:
http://reefs.org/phpBB2/viewtopic.php?t=124910

The sponsor Len is talking about in this thread has some ricordeas that look really sweet. - They'll do fine under those lights (as long as water quality is kept up) too.. - Of course, if your LFS has some ricordias its always good to support the local economy too.. 8)

 

[ElMonoCalvo]

Yep, the polyps are zoas. I was checking out that site earlier and while I'm ready to add I'm torn because there are a couple nice LFS within an one to two hour drive of me.

I already have the replacement bulbs but it sounds like I could just gauge by the health of the tank when to replace them instead of doing it on a set schedule.

 

[Anonymous]

Thanks for the input GratefulDiver.

I've got good corralline algae growth and a small cluster of polyps and xenia that were recently added seem to be doing well under the current bulbs. The plan now is to swap out one of the two bulbs every six months.

then you'll always have one sub par bulb running

change them BOTH every six months

 

[ElMonoCalvo]

The reason I was going to swap out one at a time was to minimze the intensity change of going from 2 subpar to 2 full strength bulbs in one shot. I guess if the the bulbs are changed out before they get to "subpar" it shouldn't matter, right?

 

[kgross]

I think changing 1 every 6 months will be fine. That means you are running each bulb for 12 months, which is not to bad for PC bulbs, on hopefully electronic ballasts.

Kim

 

[Anonymous]

The reason I was going to swap out one at a time was to minimze the intensity change of going from 2 subpar to 2 full strength bulbs in one shot. I guess if the the bulbs are changed out before they get to "subpar" it shouldn't matter, right?

don't worry about any intensity changes-isn't an issue, especially with fluoros

phosphours in ALL flouro bulbs begin to degrade almost immediately, and will be giving off FAR less (usable) light after 6 months, regardless of what you may see manufacturers claim

iirc, there should be some material on aaolm about fluoro outputs/ degradation by either sanjay joshi or dana riddle in the archives

but the bottom line is that if light is as critical a thing as it is, why not have it be at its maximum as often as possible ?