Aquarium Lighting - When to Replace

[c0mputernick]

Ive been running my reef tank for over a year now and its coming along nicely. I have 3x250w MH lighting (20k - left, 14k - right, 10k middle)

I have heard that these bulbs are only good for about a year and then start putting off different spectrum lighting that is no good for corals. Is this true? Does everyone replace their bulbs every year? Seems like that could get expensive at $100+ a bulb. I just dont want to start loosing corals. My tank really hasnt "taken off" the only things that seem to do good in my tank are my zoolanthids and my one clam. (and of course that kenya tree that drops shoots everywhere) but everything else hasnt grown since ive put it in there, and my zena's just shriveled up and disappeared. Some of the problems were from the learning process with getting the cal/dkh levels right, and ive finally got an auto top off rig working, so my tank is doing alot better, growing alot more coraline algae (slowly).

So now that ive kinda got the basics down, i dont want to start losing things now because the lights are over a year old. What is recommended?

What does everyone else do?

Thanks for the advice.

 

[glxtrix]

I replace mine on the 1 yr mark. I run halides. Some people are more crazy with replacing them and do 6 mos. And some run theors much longer, like 14+ All depends really if you see any change in the corals health and if algae is starting to kick up.

 

[dannybradley]

The best way to know is by using a Quatum Meter to check the PAR values over a period of time to monitor the decline. You can use a lux meter for the same general purpose, though a quantum meter is more useful overall.

The rule of thumb is to replace halides about every 12 months. They experience red shift, where there light spectrum degrades to that of a redder spectrum, which tends to promote nusiance(micro) algae instead of coral growth.

 

[c0mputernick]

Ok with that said. What bulbs are recommended and where is a good place to get them from? Ive heard german or european bults are better than others. My reasoning behind the 10,14,20 combo was to put as much diverse light as i could. its my understanding that the 20k penetrates the water deeper, or simulates deep coral light. I dont really know what coral would need what light, so i got one of each. i dont know what coral ill have in the future or what my current coral lighting needs are. so is this a good setup? or should i go with all 10s or all 20s etc? I do like the blue tint the 20 puts out, but the tank looks alot dimmer without the 10k. I have the 14 and 20 on from 8am to 10pm and the 10 on from 2pm to 7pm. Was going for a sunrise, mid day, sun set effect. dont know if ive achieved that or not. its all a big experiment for me ;-)

thanks for the info.

 

[dannybradley]

This is a very complex question, and some of it will come down to preference. The problem is, is that what I'm posting is true in most cases, but not all. Another issue is that different manufacturers' bulbs are different colors while branded the same.

10kk bulbs will have a higher PAR output than 14kk, 15kk, and 20kk bulbs. They provide a white light. They are considered full spectrum, as they represent the full color spectrum in their output.

14kk/15kk provide a crisp ice white/blue color. They tend to have the lowest PAR of the spectrums availible, unfortunetly. Your best luck with them is to run higher watt 14kk bulbs to increase PAR while providing the color you want.

20kk bulbs are a very blue bulb that yield higher PAR than 14kks, but less than 10kks.

Are these HQI or Mogul?

 

[c0mputernick]

I am unsure of what kind they are, the are single ended if that helps.
I know one is an aqualine, the 14k i think. I dont know what the other two are, they are unbranded. I just know they were suppose to be 10k and 20k when i bought them. there are so many brands i dont know what i should replace them with. is there ones that lasts longer than others? (given that they are all burnt the same length of time of course)

 

[dannybradley]

I would hesitate to say that one brand would last much longer than another. The single ended bulbs are also known as mogul socket. It's actually 10kk, as it's really 10,000k, but don't worry about it. Chris(Mojo) posted that once and I'm too anal not too...

XM makes a great 10kk with respective PAR output. Hamilton also makes a nice 10kk. Do NOT buy Hamilton 14kks, they have very low PAR ratings. Aquamedic makes a great 20kk HQI, I have not tried their mogul 20kk HQI.

Now that I read back, it's a little counter productive the way you have your lighting spaced out, unless you're trying to keep lower light coral under the lower spectrum bulbs. I don't prefer the asymmetrical lighting look. You would probably get a better blend if you did 10kk-20kk-10kk. Just wait for some other people to chime in on bulbs. EVeryone has their own opinion on them.

 

[schwaggs]

Actually, I think the K for Kelvin should be capitalized so it should be 10kK, but I'm not 100% on that...

The last time I replaced my 14K Phoenix DE 250W bulbs I rented the club PAR meter. If I remember correctly, the PAR of the old bulbs were within 10% of the new bulbs and they were 14 months old. The next time I replace them, I am going to do it at 18 months and measure again. I suspect that the ability to go much past 12 month varys based on bulb brand, spectrum and ballast brand/type as well as photo period.

 

[cameron]

If you like a nice white, XM 10ks are hard to beat and they throw great PAR for a 250w. I never really found a bulb in the blue spectrum I liked.