Old VHO bulbs

[FarmerTy]

So, was thinking to myself, bought this complete system with a 250-watt metal halide and 4 VHO bulb setup. The VHO's are strictly actinic and I have them on a 11-hr schedule with 8hrs of the metal halide.

I really only use the VHOs for sunrise/sunset effect and actinic supplementation for a slightly bluer look. I am starting to have suspicions that the spectrum change (VHOs change fast supposedly, within 6-12months) is causing unhappiness to my coral population. Not to the point of anything not looking good, but just a general irkedness I can see in the many different species of coral, especially my zoas. Reason being is that prior to the lights coming on, all the corals are opening in anticipation of the light, they all look great, then the actinics come on and they are still open, but just look slightly pissed.

So, with that in mind, I was wanting to throw this problem out there to see what everyone on ARC has experienced or know of to see what you guys think. Do you think its possible for the VHO's to cause this irkedness (no idea the age of the bulbs)? The fans are tied to the VHO bulbs so I haven't gotten to try to run just the metal halide by itself, but I'll get around to it this weekend and test for a few weeks without VHOs.

In the long-term, it would almost make more sense to switch to T-5's because they don't change spectrum as fast as VHO's if I am only using them for actinic supplementation, especially since I have have an IceCap 660 ballast that can run either.

Let me know what you think. Thanks in advance for taking the time to roll this one around the old noggin' and share your thoughts with me.

-Ty

[offroadodge]

?.. hvnt heard of it. Ill turn mine off and see. Havnt had any problems with VHOs. Possible i guess

[+mcallahan]

Aging bulbs can certainly have spectrum shifts, which your corals probably won't like as the new light would be a change from what they know and have come to love.

For that reason, I pull my bulbs eery 6 months, no questions asked. People think I'm nuts for doing it, but you won't know your bulbs are dead till your corals start looking like poo. Then by the time you replace them and recover your corals, more time as gone by. I'd rather just avoid the problem all together.

[Timfish]

Aging bulbs can certainly have spectrum shifts, which your corals probably won't like as the new light would be a change from what they know and have come to love.

For that reason, I pull my bulbs every 6 months, no questions asked. People think I'm nuts for doing it, but you won't know your bulbs are dead till your corals start looking like poo. Then by the time you replace them and recover your corals, more time as gone by. I'd rather just avoid the problem all together.

+1 although I'm content with 12 - 14 months with my T5s. I think it's a good idea to upgrade to T5s from the VHOs, last time I played with the numbers yearly bulb cost was significantly lower running T5s and I think the lumens/watt favors T5s over VHO but I haven't played with VHOs in a long time so I may be misremmembering (it's not alhziemers it's attitude). I also don't think it makes sense to try to save to much on bulb cost when you consider the intrinsic and aesthetic value of your animals.

[JamesL]

This is a very timely thread. Lately I have been having some issues with my bubble tip anemones not being happy... and one of my LPS brains has not been as inflated as usual. So I went searching today to see when I last changed my MH bulbs... and it was June 2009! Needless to say, I have new bulbs on the way now

I agree with Mark, in that it is probably better to have a set schedule for changing bulbs, before you see effects like this.

When I had my 24g tank with CF lights, I would see a boost in algae when the lights started getting old. And come to thing of it, I am seeing that in this tank too. I am getting a type of hair algae, but only in the shadows on the back wall.

[FarmerTy]

I guess just to clarify, my metal halide bulb I replace every year, no matter what. But I really don't consider the VHO's part of my lighting system, just sunrise/sunset and actinic supplementation.

Regardless of whether I think of it as part of the system or not, it is... so I'm was just wondering what opinions were out there on the VHO's and its effects of the change of spectrum. I'm treating them like accentuated lighting, almost like LED's added to the system for glimmer. Again, doesn't mean that their fluctuations in spectrum will not affect my system.

Timfish, thanks for the input about the VHO's. That was what I was reading between T-5's and VHO's, in the long run, I'm paying more for the VHOs. Thanks all for the input received so far. It's helping me narrow down my next move.

-Ty

[JamesL]

Even though they are not part of the main lighting, their spectrum will shift over time (as you indicate). And this shift will most likely be into a range that is more favorable for nuisance algae. So I would put them on a replacement rotation also.

Now this will not "harm" your corals ... more just enjoyment of the tank