Do HPS bulbs get wekaer

So do HPS bulbs get weaker as time goes on, before they blow out, or if they work, they are at full strength, and when they go they just blow out? My HPS bulb was used for about 4 months 15 years ago, then sat on the shelf. It still works 15 yrs later, but I am wondering if I am not getting full strength out of it, and should change it now, or should I use it till it blows out?

get a new one,all bulbs are upgrade'd,now'a'days

Yeah, def get a new bulb. Way better tech since 15yr ago. What's the wattage BTW? and are you using it for veg or bud. To answer your question, HPS lumens do drop over time and the bulbs start to "cycle" when they go bad. The only "HID" bulb that doesn't have a lumen drop are low pressure sodium.

Its a 400W HPS. Ok, Lumens drop over time. But is it over time while using the light, or lumens drop over time even with a bulb that just sat in storage? Using the light for the whole grow, veg and flower. Its all I got. I would prefer to not replace the bulb till it blew out, but if sitting in storage without use degraded it, then I guess I should. I just told my wife I was finally done spending money on this setup except for the last remaining purchase of a carbon filter. LOL. Now I gotta spend an extra 100 or so on a bulb. Boy I am gonna owe her a lot of shoes. lmao. Thats how we barter.

As the name implies, a High Pressured Sodium bulb uses sodium in combination with mercury to provide the light in the arc tube (the tube in the center). Over time, that pressure can dissipate (esp 15 years) through small imperfections and warping of the glass and mogul end. If you are noticing any difficulties in starting up, or staying ignited (cycling as its referred to), then its definitely time to change. Also, over time the spectrum of the light will shift and the intensity of light will diminish the more the bulb is used. If it is working fine and your lumen output is what you need, then why waste a working bulb? Good luck!

aficionado said:

As the name implies, a High Pressured Sodium bulb uses sodium in combination with mercury to provide the light in the arc tube (the tube in the center). Over time, that pressure can dissipate (esp 15 years) through small imperfections and warping of the glass and mogul end. If you are noticing any difficulties in starting up, or staying ignited (cycling as its referred to), then its definitely time to change. Also, over time the spectrum of the light will shift and the intensity of light will diminish the more the bulb is used. If it is working fine and your lumen output is what you need, then why waste a working bulb? Good luck!

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Hey thanks for the reply. The reason I asked the question is because it does seem to be running fine. Starts up fine, stays lit. The first test run I left it on for about 12 hours. This last test run its been on for about 36 hours. I do not know if the lumen output is sufficient though because my grow has not started yet. Just doing test runs of all the equipment to make sure everything works and to get a feel for everything before anything living goes in there. Don't want to be a murderer. lol. And not that this means anything, but the light is still bright as hell, I wear my oakleys when unzippering the tent. So maybe I will start the grow with the bulb. If it is a bit weaker, that may even benefit me early on, since I am putting seedlings directly into their medium and into the tent with that light (after germinating). I will get a bulb as soon as I can so I have it to replace when needed.

Its good to change out your bulbs every year

i try to replace mine every 3 to 4 grows..

You can check the (lumen) output if you had a meter, but it'd be cheaper to just get a new bulb off the net. It might be working well now, but just remember, it's old and most likely has lost some of is vacuum over time, which might affect it's operation. Kinda your call on replacement...i know i would though. New 400W HPS bulbs put out 51,000 lumens when new just fyi. Or if your using it for veg, looking into getting a Phillips ceramic MH conversion bulb. I do suppose if your grow is pretty small, you'd be fine just running it until it dies though.

I know mine is starting too get weaker. Doesn't seem as bright as it used to be.. but then again a certain amount is just your eyes getting used to the light.. but in fact, HPS/MH bulbs do get weaker and weaker the more they get burned.. the more they get weaker.

I have two 150watt HPS Grow lamps from Sun Systems Inc. The one on the left, that bulb burned out after only 90 hours of use.. but i think that bulb was a dud to begin with. It was meant to fail early.. hehehe. But the one I have next to that one.. it sits on the right hand side of my grow tank (old aquarium lined with the dull side of tin-foil) and yeah I know.. I need to rip out the foil and buy some Mylar and I will do that eventually.

Anyhow, yes.. to answer your question. They do fade out.. very slowly.. but they do eventually burn completely out.