HPS Bulb Help

I have an Apollo 600w digital ballast I got off Amazon a few grows ago, I decided to replace the bulb with a fresh one and one that is designed for growing. I found Amazon had a 2 for $25 deal on the Vivosun 600w HPS bulbs so I got them (I know that isn't the $100 per bulb Hortilux, but I'm not trying to spend $100 on a light bulb). I made a wing canopy fixture to replace my cool tube since I didn't really need it, so the bulb socket is brand new. I screwed the Vivosun bulb in and turned it on, the bulb started and ran for about 5 or so minutes then it shut off, a minute later the ballast would reset and try again with the same result. That happened about four times before I thought about turning it down to 75% (450w), the bulb stayed on consistently at 450w. I tried the other bulb the next day and it ran fine at 600w but today I come home from work and it is off and the room is cold like the light hadn't been on at all (the ballast was running though). My question is, what would make the bulb not work at 600w but be fine at 450w? I'm returning them but If I can avoid this again that would be nice.
Thanks everyone.

it`s either the bulb or the ballast

I would guess your ballast has some issues maybe a cap inside it is burnt out or something ?

Had a 1k hf hps that was acting funny, started plusing on 1000-super so we dropped it to 1k was ok for a few months but then it stopped working I`m guessing it still might do 600w but I`m not wasting money on another new bulb for it, it blew a 1000w mh that was under a year old a few months ago, so whacked up a 600w hps just in out veg/ back up flower room, might build a 600w led cob unit to replace it one day

Thanks for the response. The old bulb was working just fine at 600w, I just replaced it to put a fresh one in, there wasn't any issues I was trying to fix with this swap.

Maybe just a defective bulb. Just do an exchange thru amazon before the time period for refund runs out. Amazon is fantastic for dealing with, say it was defective and they'll pay the return shipping and just send it back and order a new one.

The new bulb seems like the only variable that changed from when it worked. I'd say you got a bunk bulb as well if I had to guess.

Unless it's just shitty construction, that's weird that both bulbs are doing that.

bfeeney said:

Unless it's just shitty construction, that's weird that both bulbs are doing that.

Click to expand...

I just reread your first post and I realize now it is doing it with both bulbs now. If thats the case then yes, its your ballast.

My ballast worked just fine with the original bulb at 600w

Get an electrical meter and test the output at 75% and 100. It should be around 525/675