The great dimmable ballast debate.

[Batcave]

I have used different dimmable ballasts for the last 2 years and have used the dimming feature when heat has been an issue, but I see many conflicting posts regarding the dimmable feature of ballasts. Some say you have to change the bulb out to a lower wattage bulb when dimming, some say use the same bulb just dimmed, others say the dimming feature is supposed to be used in the last few weeks of flower as a boost, and yet others say it degrades the bulb, or even lengthens the life of said bulb.

The reason I am bringing this up is that I just noticed my 1000w JDL ballast has been set at 75% for around the last 2 months, guess I dimmed it and forgot to put it back to 100% (stoner moment). Funny thing is that I have seen no difference in my plants or yields, everything is still just as fat and healthy as when it was running at 100%.

I asked awhile back about if dimming the ballast changes the Kelvin rating and the ballast makers response was no they didn't see any difference.

I would like to hear anyone elses experience or theory on the dimmable features of our digital ballasts.

BC

 

[JJ Bones]

IMO, dimming does not harm the bulb. Pushing it past it's wattage can diminish the lifespan, possibly, however dimming shouldn't cause an issue. And I would just use a 1000w bulb in the 1000w ballast, nothing lower.

To really know, you'd need to do a side by side @ 75% vs 100%, and get yield differences. It won't be too noticeable via eyeballing, IMO. Obviously strain dependent.

 

[Batcave]

Thanks JJ, that is my thoughts as well. I always figured "super lumens" would degrade the bulb faster, dont know how much faster but its expected. My original main concern was that lowering the wattage of the 1000w bulb would possibly change the Kelvin and not grow as efficiently, but the ballast maker says otherwise.

 

[Muttt]

I've been ballast shopping lately and noticed two different style of digital ballast. The first one is like the one you mention. It has a 50, 75, 100 and super setting. All the info I gathered about them says that you leave the bulb in and just change the setting for less light. The other style I've found is a select a watt type. These could be set for 1000w, 600w and 400w. When you change the setting, you must change the bulb to the appropriate wattage.

 

[JJ Bones]

I've been ballast shopping lately and noticed two different style of digital ballast. The first one is like the one you mention. It has a 50, 75, 100 and super setting. All the info I gathered about them says that you leave the bulb in and just change the setting for less light. The other style I've found is a select a watt type. These could be set for 1000w, 600w and 400w. When you change the setting, you must change the bulb to the appropriate wattage.

I have never seen a digital ballast that would require three different bulbs. Which one are you speaking of, out of curiosity?

 

[Muttt]

I think it was the galaxy (not sure). They have them at the hydroponic store in town here. (way overpriced) Anyway, the guy at the store explained to me that you needed a different wattage for each setting. I could be wrong ..... since I am taking this guys word for it. But, it's the only ballast this shop sells. For all I know, this guy could have been talking out his ass.

I was actually going to buy one (at his shop). But, I didn't like the idea of needing three different bulbs. Not that I would need them anyway. I don't think I'll ever use my 600w on anything other than 100% since it's about the right size for my grow box.

 

[Batcave]

I believe Mutt is speaking about ballasts similar to my 600w from GrowOp Tech., even though it says 360w, 400w, 600w, and Lumen+ on the dial the ballast maker said to just use a 600w bulb and adjust it.

 

[JJ Bones]

No Mutt is talking about needing three bulbs for each dial.

Mutt, the guy @ the shop is mistaken, not sure what he's thinking. If you need a ballast let me know, I can help you out.

 

[Batcave]

No Mutt is talking about needing three bulbs for each dial.

Exactly, have seen numerous people post that you are suppose to change the bulb to whatever wattage you lower it too which is FALSE by what the makers of the ballasts I have used have told me. 600w dimmable uses only a 600w bulb, 1000w dimmable uses only a 1000w bulb, etc...

 

[JJ Bones]

Exactly, have seen numerous people post that you are suppose to change the bulb to whatever wattage you lower it too which is FALSE by what the makers of the ballasts I have used have told me. 600w dimmable uses only a 600w bulb, 1000w dimmable uses only a 1000w bulb, etc...

Right, gotcha. False indeed.

 

[Batcave]

If you had a 1000w dimmable and HAD to swap bulbs to dim it then it would cost as much for the set of bulbs as it cost for the ballast. Never seen a 750w hps bulb, but I do know that GE makes a 750w MH

 

[Muttt]

I have no idea how this hydro shop stays in business. If he's putting out really bad info like that.