How long can I expect my bulbs to last??

I have 2 fluorescent 48" t12 40 watt bulbs in some endcaps and powered by a 490XLHTCP MAGNETEK ballast. I have had the light up and running for a few months and have gone through 3 bulbs already. Is this normal? Is there different wattage I need to be aware of? I know little about electricity. Any thoughts would be appreciated. 4500 hour bulbs should last about a year at 12 hours a day per my calculations.

I dont know much about the t12 cause im running pc's for the time being but im pretty sure depending on the quality of the bulb they should be good for at least a year and they will be bad before they actually blow so i think you have another issue.

I googled the ballast number.The ballast uses T12 HO bulbs(60w) and not the normal output T12 you are using now.That is probably why the bulbs are burning out so fast.As far as T12/HO bulbs goes,I don't know of any company still making them for reef aquarium.

Ok, freak can I use VHO bulbs in a HO ballast?

i bet you could but they would be under powered but that may make them last longer. but reef will no more than me about this.

Sorry,I don't believe so.I don't think it has the strength to ignite the bulb(110w).The bulb might flicker but not ignite.There are HO bulbs out there,just not for corals/reef aquarium.If you are using this on a fish only then any HO bulb will do.Maybe try contacting the manufacturer.You maybe could change the endcaps and use T5-HO(54w) bulbs instead.

These are to go along with my 2 175 watt metal halide pendants. I was using them with actinic bulbs. Can I use any of these bulbs for actinics and have them last?

Yep,good job on finding a company still making HO aquarium bulbs.They should last the normal 6 months or a little more.I sure don't like some of prices for those bulbs.

Well considering the fixture and ballasdt were free when I bought the tank, I am not too worried. I guess I will start shoping for a new fixture. In the meantime though, I guess mail order is my only option.