in my basement a florescent fixture was damaged by waterline repairmen. they broke one of the 2 bulbs in the fixure. so, being stupid i bought an ALTO bulb (T12 8ft.). the other bulb in the fixture is at least 10 years old. when i turn it on the older bulb is brighter than the ALTO! they are the same wattage - 60 watt. what is going on here??

The lamp is the problem, ALTO lamps are known around here to be real trouble!

ok what should i do

As they have less mercury, the pressure of mercury when vaporized is lower, so less light.

would u suggest replacing any existing fixures w/ alto when they go out or non- alto

Non-ALTOs for sure! Even the GE Ecolux tubes are better!

ok cool. thanks because i was gonna go all alto. guess i was wrong.....

Yeah I tried to capture a picture of some Altos installed in an 8' slimline fixture under an eave this morning, but the photo didn't turn out. Temperature was about 20 degrees Fahrenheit this morning. Lamps were replaced with these Altos last summer and have steadily lost mercury...were dim and flickering even in warmer weather, but this morning, one glowed purple, the other was just very dim and you could see the electrodes glowing brighter than the rest of the tube. Sad!

I have a pair of USA made F20T12 GE Ecolux in a trigger start fixture and also a pair of Canadian F32T8 Ecolux in an electronic instant-start fixture, both in my garage....temperature was just below freezing in the garage and they worked no differently than the older GE fluorescents with full mercury doses that I have in all the other fixtures. No striations, no red color, warmed up to normal brightness just as quickly as the others. The worst cold-weather performer that I have is one particular old Philips F40T12 in my Tulamp preheat fixture, it is the dimmest of the four and sometimes flickers a lot or even restarts a few times at very low temperatures, but will be as bright as the others when fully warmed up.

crap, I just bought 2 Alto f96T12 cool white bulbs they are 60W I noticed they are more flickery every day, as they are turned on several times per day.

I generally avoid Alto's whenever possible. One exception, I bought a couple cases of F96 Alto's for work a few years ago and they seemed to perform ok so I was lucky to get a decent batch I guess.

I generally avoid Alto's whenever possible. One exception, I bought a couple cases of F96 Alto's for work a few years ago and they seemed to perform ok so I was lucky to get a decent batch I guess.

I would say good pieces, as the mercury dose (so undetected underdose error) is more piece-to-piece then batch-to-batch dependent.
Or you are using ballasts not stressing them as much, so the mercury depletion is slower.
Or your lanterns run lamps hotter, so are capable to get some mercury vapors from "any corner", but this is really a speculation.