the only time i've seen an alto kill a ballast was at my elementary school way back when. they had just converted all fixtures to F34T8 and put in Philips Altos. all of a sudden one day the whole light turned a purple color and the 4- bulb fixture went out. it never got fixed, probally because the janitors were to lazy to even fix a ballast. then one time they put instant start T8's on a rapid start converted T12 ballast and they said it wouldn't work because of a shot to the lamps. if thats true, t i wonder why they couldn't just replace the socket wiring. i posted this topic of to warn people maninly of T8 altos, because ive never had a problem with T12s...

So far I've been lucky,my ALTO's haven't killed any ballasts yet,and I've been using them for a good number of years now.I use them because they are the only cool white F40T12 lamps available here that are 40W and not the dim energy saving 34W lamps.

i have the same problem here.

I remember of a single F40 striplight that used to hold a Philips fluorescent, I don't know if it was an ALTO or not. That was back in 1999 or 2000.

i changed my mind. i like alto's now! 

Well I see ALTOs everywhere! Not too long ago I saw in a place full of ALTOs 6 GEs from the 70s, they were warm white. Running 24/7 for 30 years and almost no blackening!

the less you turn a fluorescent bulb off and on, the less the ends blacken. also, the green endcaps of alto's looks cool!

I find these green endcaps cool looking as well! But they don't look good in any fixtures...

So far I've been lucky,my ALTO's haven't killed any ballasts yet,and I've been using them for a good number of years now.I use them because they are the only cool white F40T12 lamps available here that are 40W and not the dim energy saving 34W lamps.

This depend on the ballast type and protection - how it is sensitive for lamp voltage rise (higher then nominal - e.g. both electrodes emitter loss), fall (lower then nominal - lower wattage "ECO" retrofit), rectification (one electrode emitter loss) and filament breakage (typical for old lamps - they have huge amount of both emitter and mercury, so it was their weakest point) - i don't exactly know, how exactly ALTOs behave differently then "regular" ones.
But (what i assume as) good ballast should be designed to safely (for both the user, as well as the ballast itself) handle all these failure modes, so should or work properly with, or shut OFF, the improper lamp (so e.g. ALTO on non-ALTO designed ballast), but when connecting back the correct lamp, it should properly work again (might require manual "reset" for it - e.g. the thermal protection switch).

The Open circuit voltage in Electronic ballasts goes up as the bulb becomes more mercury starved. That causes the ballast failure after a couple hundred hours of that happening.

i remember a ballast went out, (a light in a display case, built in the wall, they have tons of those in the newer building at school) and i saw a janitor replacing the ballast. lol. and in one room at school, a ballast is bad, and the light flashes. (i mean its on, it just blinks off now and then and its off for a milisecond? lol. wonder if they are altos.

Good quality ballast has to sense this and shut OFF the lamp. It is not as difficult to make such protection (sense the lamp voltage and shut OFF when too high or unsymmetrical), well except the cheap selfoscillating crap (like this ). Such design is acceptable for CFL's, where it does not have to last longer then the lamp

The Open circuit voltage in Electronic ballasts goes up as the bulb becomes more mercury starved. That causes the ballast failure after a couple hundred hours of that happening.

I have some F32T8CW Altos that are mercury starved right out of the box! When I cold start them, they are dim in the center but full brightness at the ends. As they warm up, they function normally. My F32T8 ballast is a rapid start magnetic one made by Universal. How would a mercury starved lamp affect a magnetic ballast? However, I have no complaints about T12 Altos. My dad's garage has a set from when they first came out and they are still bright and show no signs of mercury starvation. I also have a set of Philips Daylight Deluxe Alto T12's that work perfectly. It seems only the F32T8 Altos are crap.

Well, I have found a pair of Sylvania F32T8/CW, one 741 the other 841. Both are ecologic and last December when I first tested them they acted like you said. Today they are prefectly fine. That "warm-up" mercury starvation generally disappears with use (I mean the more you run it, the less the problem is).

I have some F32T8CW Altos that are mercury starved right out of the box! When I cold start them, they are dim in the center but full brightness at the ends. As they warm up, they function normally. My F32T8 ballast is a rapid start magnetic one made by Universal. How would a mercury starved lamp affect a magnetic ballast? However, I have no complaints about T12 Altos. My dad's garage has a set from when they first came out and they are still bright and show no signs of mercury starvation. I also have a set of Philips Daylight Deluxe Alto T12's that work perfectly. It seems only the F32T8 Altos are crap.

All ALTOS are like that, it's normal because most of the mercury may still be in the dosing capsule attached to one of the electrode guards, it's opened when they seal the lamp some cases it doesn't open at all, and the lamp is ALWAYS mercury...less...don't know how to put that. but your case seems normal, I've seen most altos and even non altos do this. it's the dosing capsule that does it.

Well, I have found a pair of Sylvania F32T8/CW, one 741 the other 841. Both are ecologic and last December when I first tested them they acted like you said. Today they are prefectly fine. That "warm-up" mercury starvation generally disappears with use (I mean the more you run it, the less the problem is).

I also have a bunch of Sylvania F32T8/CW 741 ecologic lamps that start with the ends bright and the centre dim. They gradually warmup the full brightness. This warmup stage doesn't seem to go away in mine. I don't have a problem with the T12 low mercury lamps though.