light pricing........4ft fluorescent tubes

Overdriving your ballast isnt really a good thing to do.It cuts the life of th unit by more then half.The bulbs burn out quicker and you loose a bulb for each overdrive you do.Each 2 bulb ballast becomes a single ballast.The benfits dont really outweight the issues it causes and its a big fire hazard in your house.

FilthyFletch said:

Overdriving your ballast isnt really a good thing to do.It cuts the life of th unit by more then half.The bulbs burn out quicker and you loose a bulb for each overdrive you do.Each 2 bulb ballast becomes a single ballast.The benfits dont really outweight the issues it causes and its a big fire hazard in your house.

Click to expand...

Not worth buying the over diven ballests just stick to the reg HO T5s, they are great

Cool man my wallyword has them on sale for $7 right now, and i almost picked one up yesterday...If i dont get my heat issues taken care of im goinng to switch my lights to a couple of them....Im on my way to get a couple today...

space_weaseal said:

Cool man my wallyword has them on sale for $7 right now, and i almost picked one up yesterday...If i dont get my heat issues taken care of im goinng to switch my lights to a couple of them....Im on my way to get a couple today...

Click to expand...

so you arent going to try to fix heat issues then?????? if i dont get it fixed, and then im going to get some sounds like An abort as far as effort goes

Ok, here goes:

Is it a myth that overdriving is inefficient? Fluorescent lights operate most efficiently at a particular power level, and then progressively less efficiently at higher or lower power levels. Tubes are typically manufactured for a nominal power level near the peak of the efficiency curve. High Output (HO) and Very High Output (VHO) are designed to operate at a nominal power level above the most efficient power, these are overdriven lamps by another name. That's worth remembering when you are drooling over a 54W T5HO lamp, a standard 28W T5 is considerably more efficient!
The most efficient power level for a 48" T8 tube is around 35W-40W, and it operates pretty close to maximum efficiency anywhere from about 25W-50W. Note that this type of tube is generally run at 28W on power factor 0.88 ballast, as a "power saving" feature although it is in fact less efficient than running at a higher power. The power saving comes from being a direct replacement in the same fitting for an old 40W tube or a somewhat less old 36W, 34W, or 32W tube.
So a T8 tube running at 54W is really not far from the peak efficiency levels and may actually be more efficient than running at the "out of the box" 28W power level. Certainly less efficient than running at the designed level around 35W-40W though. Some people have made a lot of running with this fact and tried to make out on the basis of a single case that overdriving does not reduce the efficiency of a fluorescent tube. There is also a much referred-to web article by someone who claimed to demonstrate that overdriving was in some cases more efficient and generally not much different from running a standard tube, although the experiments were actually flawed and really only proved that it is incredibly wasteful to run a single tube off a four-tube ballast
Overdriving a 40W T12 significantly reduces the efficiency, these tubes are not generally underdriven by design and doubling the applied current takes them way beyond the most efficient part of the power curve. The same applies doubly so when you 3x or 4x overdrive, or if you were to overdrive the already overdriven T5HO tubes. You may be able to track down in the specifications of some manufacturers actual light output curves against the applied current, or lumens/W curves against current or power. You will find that peak efficiency comes at around 400mA, or a little less for thinner tubes. Off the top of my head, I think 400mA is the nominal current for T12 tubes while T8 tubes (ballasts really) in the USA run nominally at 265mA for 32W power and obviously at an even lower current (about 240mA) on a 0.88 ballast. You see that a 2x overdriven T8 could be running at only 480mA while an overdriven T12 would be more like 800mA. One is near peak efficiency, one is way off.
Hope that wasn't too confusing



Ten myths of growing under lights - Growing under Lights Forum - GardenWeb

that is alot of words!
Too many for my comprehension skills... which are that of a 4 or 5 year old... I forget... maybe 2? -4?

Basically overdriving is bad

thanks fletch! even I can unnderstand that... I read the previouse post 2 times... and so far what I rememeber is something about 25 W and ... ... ... thats it really...

Basically that long post above says that the T5 bulb that everyone is drooling over is overdriven by design.
So there is nothing wrong with overdriving, it is a good thing, because all T5 HO bulbs are overdriven. However, T8 bulbs can also be overdriven easily, at much less cost.
The post says that in between 25 and 50 watts, the T8 bulb responds in a linear manner, the more juice, the more light. At 54 watts, it starts not being able to put out the same lumens per watt, but it still is brighter. I put the question to another forum where people are more knowledgeable about it than I am, and I cross posted the answer to clear up the confusion here. So whoever added the Bullshit tag, should remove it, because this is all very well researched, and there is no bullshit involved.
Additional T8 ballast can be obtained cheaply from e-bay, $50 for 10, and this is enough to overdrive 10 2 lamp T8 shoplight type fixtures. I invite you to follow the links if you don't quite follow what I'm saying, or need more details. When hooked up like this, the ballast has a bunch of transistors that sense the different load, and respond appropriately. So the ballast is actually UNDERDRIVEN and stays very cool, while the lamps are OVERDRIVEN and heat up a little, but a gentle fan on them will keep them cool. There is absolutely no risk of fire, nothing close. So please remove the bullshit tag from this thread.

Ten myths of growing under lights - Growing under Lights Forum - GardenWeb
I have found the BEST cheap flourescent ballast/fixture

I do not grow pot and do not advocate breaking the law. The above lighting system is strictly for my indoor rose garden.

object16 said:

Basically that long post above says that the T5 bulb that everyone is drooling over is overdriven by design.
So there is nothing wrong with overdriving, it is a good thing, because all T5 HO bulbs are overdriven. However, T8 bulbs can also be overdriven easily, at much less cost.
The post says that in between 25 and 50 watts, the T8 bulb responds in a linear manner, the more juice, the more light. At 54 watts, it starts not being able to put out the same lumens per watt, but it still is brighter. I put the question to another forum where people are more knowledgeable about it than I am, and I cross posted the answer to clear up the confusion here. So whoever added the Bullshit tag, should remove it, because this is all very well researched, and there is no bullshit involved.
Additional T8 ballast can be obtained cheaply from e-bay, $50 for 10, and this is enough to overdrive 10 2 lamp T8 shoplight type fixtures. I invite you to follow the links if you don't quite follow what I'm saying, or need more details. When hooked up like this, the ballast has a bunch of transistors that sense the different load, and respond appropriately. So the ballast is actually UNDERDRIVEN and stays very cool, while the lamps are OVERDRIVEN and heat up a little, but a gentle fan on them will keep them cool. There is absolutely no risk of fire, nothing close. So please remove the bullshit tag from this thread.

Ten myths of growing under lights - Growing under Lights Forum - GardenWeb
I have found the BEST cheap flourescent ballast/fixture

I do not grow pot and do not advocate breaking the law. The above lighting system is strictly for my indoor rose garden.

Click to expand...

first and foremost in addressing this reply as the most recent reply added. this thread was not at all about overdriving ballast in any form. it was about the cost of fluorescent lights. nothing to do with the way ballast operate lights, go and re-read it.
BULLSHIT refers to the cost of the light in itself.
and now it refers to someone asking me to change my thread because they didnt care to read it carefully enough.

Eek, sorry about that. Peace brother.

Toronto hemp companies HO T5 prices
2 foot $29.99
3 foot $39.99 (I have six of these)
4 footer (with overdiven ballests) $54.99
These pices are competitive with any internet shop or hydro shop

These are all great lights and worth the cash for sure. if your getting the T5s make sure they say HO (High output) on them or they will just be another crappy flourecent light. good luck

ebay greatlightsforless has them with shipping about 37.00 for 4 t5 ho.

there are two different types of bulbs. daylight/cool (blue) and warm (red). you want either all blue or a mix of blue and red for vegging and then all red for flowering.

The local scratch n dent store here has 4 ft 2 bulb T5HO high bays with white hood for $15. I bought 2 and will try to consolidate everything into one fixture as soon as i beat this sinus infection. So in the end 4 bulb 4 ft T5HO for $30 bucks plus about 45 mins labor on my part. Since T5's don't get very hot considering using mylar to line the hood for the reflective finish.

1 red and 1 blue means 1 red light and 1 blue light, its a color spectrum thing. blue is good for growing the plant, and the vegetative stage. red is good for flowering