HPS Bulbs - Time frame for optimum efficiency and when to change it

[Jack Larson]

I have heard that you should change a HPS bulb every 12 months.
My 1000 Watt HPS Hortilux bulb is going on 18 months & it seems to be doing fine with a traditional non digital ballast.

 

[phyzix]

They are selling you bulbs, of course salesmen tell you to replace them annually.

 

[hoagtech]

Well They are right if your using them full time. Either 18 hrs a day or 12 hrs a day will put some serious wear on a bulb after a year. A bulb is typically a 20,000 hr bulb in our indusrty in spite of 50,000 hr bulb claims. after 8,000 hrs your intensity lessens, So if your runnign a veg bulb every day your gonna be at 6,570 hrs, which sounds about right if your looking to get the most out of your lights

 

[collective gardener]

I use a light meter. Every grow op should have one. When the light loses 15% brightness, I change it. This is typically 3 crops with a Digilux HPS. However, The Sun Pulse, Pulse Start 6.4k has been running for 5 crops and is still within 10% of original lumen output. A Horti with a mag ballast lasts 3 crops. The same Horti with a digital lasts 2 crops.

These are simply my observations using a $100 light meter and 1 foot spacer stick.

https://www.rollitup.org/indoor-growing/407048-20-000-watt-medical-grow.html

 

[Uncle Ben]

I use a light meter. Every grow op should have one.

Absolutely. Been preaching it for years. What brand and what's the FC rating to?

 

[collective gardener]

Absolutely. Been preaching it for years. What brand and what's the FC rating to?

I use an Extech EA33 (max 999,900 Lux) for high lux measurements, and an Extech 407026 interfaced with a PC to plot light distribution on the floor for new op settups and reflector testing.

 

[Uncle Ben]

I use an Extech EA33 (max 999,900 Lux) for high lux measurements, and an Extech 407026 interfaced with a PC to plot light distribution on the floor for new op settups and reflector testing.

Sounds like it beats the shit out of my old GE 214.

 

[Jack Larson]

I use a light meter. Every grow op should have one. When the light loses 15% brightness, I change it. This is typically 3 crops with a Digilux HPS. However, The Sun Pulse, Pulse Start 6.4k has been running for 5 crops and is still within 10% of original lumen output. A Horti with a mag ballast lasts 3 crops. The same Horti with a digital lasts 2 crops.

These are simply my observations using a $100 light meter and 1 foot spacer stick.

https://www.rollitup.org/indoor-growing/407048-20-000-watt-medical-grow.html

Hey, thanks Collective Gardener...Great Answer! I think first I'll get a meter & check my current bulb, then replace it with a new one and compare just for shits & grins. btw, what do you consider "a crop" timewise? ie Indicas - 6 to 8 weeks & Sativas, 10 to 12 weeks, (both approximately).

 

[collective gardener]

Hey, thanks Collective Gardener...Great Answer! I think first I'll get a meter & check my current bulb, then replace it with a new one and compare just for shits & grins. btw, what do you consider "a crop" timewise? ie Indicas - 6 to 8 weeks & Sativas, 10 to 12 weeks, (both approximately).

Sorry, Jack, I should've been more specific. When I say "crop", I mean a couple months. Hydrofarm makes a digital light meter for about $45 that will do pretty much everything you need. It says that it only goes up to 5000 FC, but, in reality, it goes much higher. I used to own one, and took accurate readings 1 foot away from a 1000 watt HPS bulb. It's on Pg. 65 of the 2010 Hydrofarm Retail Catalog.

 

[fletchman]

Sorry, Jack, I should've been more specific. When I say "crop", I mean a couple months. Hydrofarm makes a digital light meter for about $45 that will do pretty much everything you need. It says that it only goes up to 5000 FC, but, in reality, it goes much higher. I used to own one, and took accurate readings 1 foot away from a 1000 watt HPS bulb. It's on Pg. 65 of the 2010 Hydrofarm Retail Catalog.

Wow, so a Horti runnin 12 hours a day on a mag. ballast is good for only 6 months? Or do you mean 24 hours a day for 6 months?

 

[collective gardener]

Wow, so a Horti runnin 12 hours a day on a mag. ballast is good for only 6 months? Or do you mean 24 hours a day for 6 months?

Personally, I run em for 6 months. I know people who go for a year, and I have a friend who changes every cycle. For a commercial grower, the bulb is not that expensive. Let's say you're just getting .5 grams/watt...or an lb/light. If you're getting 3k/lb, a 10% loss of light could cost you $300. This is why my friend changes every cycle. If the bulb loses more than 3% brightness, it pays to replace it.

 

[homebrewer]

After doing this for almost 11 years, I've found that 10 months is an ideal time to change the bulbs ( I use hortilux bulbs).

 

[hoagtech]

Wow I respect that but thats expensive. I wish you shopped in my town. Id give you a good deal.

 

[Youngtree777]

Personally, I run em for 6 months. I know people who go for a year, and I have a friend who changes every cycle. For a commercial grower, the bulb is not that expensive. Let's say you're just getting .5 grams/watt...or an lb/light. If you're getting 3k/lb, a 10% loss of light could cost you $300. This is why my friend changes every cycle. If the bulb loses more than 3% brightness, it pays to replace it.

This is at 12/12 correct?

 

[Aeroknow]

This is at 12/12 correct?

I have been running hortilux in magnetic ballasts for a very long time. I also am always checking shit out with a light meter.
My 1000w hortilux bulbs are always only on 12/12.
I replace the bulbs once a year. You absolutely could go longer if in a pinch, without much loss in yield.
I replace the caps every other year. Caps fade. More so, the hotter the environment. I like running a fan aimed at ballasts, mainly for this reason. Not necessary though.

 

[Youngtree777]

I have been running hortilux in magnetic ballasts for a very long time. I also am always checking shit out with a light meter.
My 1000w hortilux bulbs are always only on 12/12.
I replace the bulbs once a year. You absolutely could go longer if in a pinch, without much loss in yield.
I replace the caps every other year. Caps fade. More so, the hotter the environment. I like running a fan aimed at ballasts, mainly for this reason. Not necessary though.

Ty for ur reply! On that note what is a cap?

 

[Aeroknow]

Ty for ur reply! On that note what is a cap?

In a magnetic type ballast, you have 2 replaceable parts. An ignitor, and the capacitor(cap)

 

[MammothGrow]

I use an Extech EA33 (max 999,900 Lux) for high lux measurements, and an Extech 407026 interfaced with a PC to plot light distribution on the floor for new op settups and reflector testing.

Wouldn't you want to be checking the lights with a PAR meter? Im curious, is their test results out there already that show if when the light intensity in lumens or footcandles drops only say %10 in 6 months that the PAR isn't way off then? Does the PAR of the bulb change at all as it gets used more? or just the intensity drops?

 

[alcohol]

I use a light meter as well. Purchased it on ebay for a fraction of the hydro store. works great.

 

[Youngtree777]

Wouldn't you want to be checking the lights with a PAR meter? Im curious, is their test results out there already that show if when the light intensity in lumens or footcandles drops only say %10 in 6 months that the PAR isn't way off then? Does the PAR of the bulb change at all as it gets used more? or just the intensity drops?

I think the Par would have more to do with spectrum?

I mean isn't PAR reading the absorbable or usable radiation by the plant? So more lumens would mean more available PAR but not better or worse PAR rating?

The other question would be..

If the bulb is depreciating in lumens or whatever you want to call the intensity, then is the PAR changing?