Anybody using 250w HQI ballasts with SINGLE ended bulbs?

[fkshiu]

I'm wondering because Sanjay's tests show HQI ballasts with SE bulbs have a significant PAR advantage over DE bulbs (probably mainly due to the fact that SE bulbs can be run unshielded). Yet I rarely, if ever, see someone running SEs with HQI.

[Chin_Lee]

yes i run 400W HQI ballast with SE 400W Reeflux bulbs. The overdriving of the bulbs with the HQI ballasts increases the PAR values for most bulbs but decreases the bulb life expectency.

[fkshiu]

Thanks Chin. I knew you couldn't get something for nothing.

Do you know approximately how much bulb life is shortened on an HQI ballast vs. a standard magnetic or electronic one?

[Bryan]

Just because a ballast is HQI does not mean it has any additional power advantage. Most cases the double ended bulbs require a HQI ballast is because of the startup characteristics of the ballast.

http://www.fortunecity.com/meltingpo...ie/38/id33.htm

quote:
Most European MH lamps require the use of an ignitor. Standard North American MH lamps usually do not need or should not be used with ignitors. Using pulse ignition MH lamps on non-ignitor systems could cause premature lamp failure. A standard North American ballast (non-ignitor system) will cause excessive stress on the electrodes. Some pulse ignition lamps may not even light on these ballasts.

[Chin_Lee]

Originally Posted by fkshiu

Thanks Chin. I knew you couldn't get something for nothing.

Do you know approximately how much bulb life is shortened on an HQI ballast vs. a standard magnetic or electronic one?

I'm not 100% sure and there are different theories out there but no scientific study have been made (that i'm aware of) to test this. I suspect the lack of testing is primarily due to the fact that deterioration of the bulbs will vary with each of the manufacturers. Having said that, the HQI increases the watts power by about 20-25% and I will be changing mine that much sooner. Instead of changing it every 12-18 months, I will change them at the 12 month mark.

Originally Posted by Bryan

Just because a ballast is HQI does not mean it has any additional power advantage. Most cases the double ended bulbs require a HQI ballast is because of the startup characteristics of the ballast.

http://www.fortunecity.com/meltingpo...ie/38/id33.htm

quote:
Most European MH lamps require the use of an ignitor. Standard North American MH lamps usually do not need or should not be used with ignitors. Using pulse ignition MH lamps on non-ignitor systems could cause premature lamp failure. A standard North American ballast (non-ignitor system) will cause excessive stress on the electrodes. Some pulse ignition lamps may not even light on these ballasts.

The use of HQI ballast with SE bulbs is an intentional decision by the users to overdrive their bulbs. If you go through the spectral plots on Sanjay's site, there is undisputable evidence that the PAR levels are substantially increased by the use of HQI bulbs on SE bulbs but at a cost of electrical consumption and prematuring life expectancy of the bulbs.

As stated, HQI ballast on DE bulbs is just a simple requirement.

On the other hand, the use of ignitors on American bulbs is another issue relating to the setup of the MH setups (including the HQI). Most aquarist will not remove nor install an ignitor due to a lack of understanding the electrial wiring in the ballast box. So most aquarist will leave the ignitor in there regardless if the bulbs they are using needs one but in most cases because the ignitor is present, it will light the bulb and make the aquarist happy not knowing that the ignitor is stressing the electrodes with each startup.

[StirCrazy]

Ok, just to clear some things up, there is no such thing as a 400 watt HQI it is actually over driven which is why the lower life expectancy. a 250 watt on a proper M80 ballast is not overdriven, but rather "properly driven which means you get more light out put and actually longer life out of your bulbs.

the reason for this is that the bulbs are based off of German specs and there power is different than ours, the M80 takes out power and replicates the out put you would get from a German reactor type ballast.

a few simple searches will take you back in time to a point where I had more money than brains and to much time on my hands and I did research and tests on all different types of lighting. you can take the same bulb type one in SE and one in DE, and on the same HQI ballast the SE will put out a substantial more amount of light. it just take up more room. it will also give you a better coverage.

when using a pulse type ballast with an American type bulb (actually a German style bulb with a starter added) you actually increase the bulb length as the pulse start is a lot easier on the bulb then the type of starter that is in the bulbs.

this was actually documented by several different people besides my self (and some a lot more reputable like sanjay) about 3 or 4 years ago. it is amazing how the old false rumors get circulated years after the fact. I changed my bulbs every 12 to 18 months and never noticed a difference.


Steve