Do i need new T5 bulbs

[tripp]

I was told at my local fish store i need to replace my T5 bulbs for my planted tank every 9 months 4 best grow results and less alge is this true or BS

[discussmith]

I will let you make a judgement with some information. Todays T-8 lamps are rated at 10,000 hours of lamp life with a 30% to 50% light degradation over that time. A standard output T-5 bulb is rated at 20,000 hours of life with a similar degradation rate. However they're more energy efficient and output more light to begin with. A 10 hr / day cycle gives approx. 1000 days (2 3/4 years) at 10,000 hours and 2000 days or approx. 5 1/2 years at 20,000 hours. Even though I don't know how many lamps or how much area you are talking about I think you can see for yourself what's going on. If this was coral we were talking about they might have more of a point. Even at a 50% degradation at lamps end by nine months you would still be at 93% output. The only true test though is with a lumen meter. There are water tight ones now becoming available to reefers who need to know how their lights are doing. Maybe you can get a hold of one and check.

[mkv]

Right on the spot.... I keep 440w of VHO lights over my reef and I have gone as far as 2.5 years between bulb changes with out any adverse effects on my corals and I keep Xenias, Brain corals, leathers, star polyps and SPS so your freshwater plants should more than do with the same bulbs for the 20,000 hrs of life....... Just my two cents....

[tripp]

U no thats what i thought an i dont have a corral tank that im sure is more critical to maintain good lighting the local fish store said the degragation after 9 months could cause alge grow thanks ill wait before buying new T5s