Lightbulb Question

[Lee Barnes]

I've got a 24g nano that's been up and running for almost 2 years now. Although the none of the bulbs have burned out, I've been reading on assorted forums that the bulbs lose their strength after a while. These are the stock bulbs that the tank came with. Should I have already changed them for fresh bulbs, or just wait until one burns out?

As far a stocking, I have 2 b&W clowns, a sixline wrasse, a bi-color blennie, assorted snails/hermits, pulsing xenia, and a clump of frogspawn. Aside from occasional green hair algae problems, the tank is all within it's parameters.

Thank you!

 

[SkiFletch]

If you run a typical 10hr/day ligth schedule with normal output flourescents, data suggests that the bulb will be down to about 80-85% of its brand-new max output after 1 year and more in the low 70-75% range after 2. The output decay curve is steep at first (they drop to 90% within a mont) but then very shallow thereafter. That being said, normal output flourescents should probably be changed sometime between 2-3 years of average (10hr/day) use if photosynthetic invertebrates are being kept.

If its a fish only, keep it till the dimness drives you crazy, the bulb burns out, the bulb flickers, or the ballast burns out. No need to replace tubes here except for personal taste.

If we're talkin overdriven high-output flourescents (T5HO) consider replacing them every 12-18 months

Very High Output flourescents (T12VHO) should be replaced every 6-12 months as these are typically driven HARD by their ballasts.

Electronic ballasted Metal Halides on the other hand can last years and still be effective. A member of our local club found that a 6 year old 250watt Iwasaki bulb (driven by a blueline electronic ballast) was still at 63% output compared to a brand-new replacement Iwasaki. While that may be significantly low, consider that the bulb is 6 years old... impressive. I'd still reccomend changing electronic halides every 3-4 years though, if only to prevent having a bulb break on you with no replacement on-hand.

Normally driven magnetic metal halides will prolly last in the 2-3 year range

And magnetically overdriven halide lighting prolly only 1-2 years

Those are all my own oppinions formed by reading articles around the 'net and by looking at real-world data generated by my local reef club and our PAR meter . While in some cases the manufacturer's reccomendation to change bulbs yearly is valid (VHO or T5HO), generally speaking they're just tryin to get you to buy more bulbs . Hope this helps you or others who wonder the same thing

 

[kkyyllee]

every 6-8 months they need to be replaced

 

[steelhealr]

About 8 monts. 6 months would burn out my wallet. The light curve does change and you may find your corals bleaching and nasties starting to grow. SHWARNING>>>>>>>>>CHANGE YOUR BULBS SLOWLY...ONE BANK AT A TIME. This will avoid 'light shock'. You can lose your corals that way. SH