Need HPS/ballast guidance

[Toripony]

On my first grow I ended up running about 700 watts of T5's and fluorescents during flowering. I know almost nothing about buying an HID light but since there's tons (literally) of used grow equipment for sale around here, I decided I might as well try a 600 watt HPS for my 2x4 grow space. 1000 watt'ers are plentiful but I only found a few 600's on Craigslist; I went for one for $50 w/ballast. From the seller's selection of 3 600 watt'ers, I picked the one with a wide hood (4 sloping sides as opposed to 2 sloping/2 straight sides) Sun Systems Magnum XXXL thinking it would have a better "spread". Then the seller went through a few ballasts till we found one with the right connector and 110 volt supply. Didn't realize until I got home that I ended up with a 1000 watt ballast (dimmable Quantuum) but a 600 watt bulb. On GWE I learned they have to match, so first thought I'd have to go back and get a 600 watt ballast but maybe I should just buy a 1000 watt bulb and run it on 75% to reduce the power consumption??? What do you guys think?

Also, I have some other questions now...
1. I CAN put a 1000 watt bulb in this model of hood, right? (has 8" cooling ports) The bulbs all have the same screw-in base, right?
2. What brand of bulb to buy? Which is the best value for the budget buck? I'm only going to use it for flowering so "enhanced blue spectrum" doesn't really matter to me (does it?).
3. Do I need to upgrade my timer from my Walmart product? I read that the cheap ones won't support the ballast's needs.

I think I have other questions but will ask later (I've forgotten them at the moment, lol).

THANKS for any advice/guidance!

[NV099]

Match the bulb wattage with the ballast wattage to be safe. You can dim your ballast if you need to, but i am not sure how much wear and tear that will do on the bulb. Go with eye hortilux if you want the best possible bulb for the flowering phase.

While using the timer that came with the ballast and hood, the cheapo timer did not start the light 2 times out of the entire grow. Unplugging the ballast from the timer and plugging it back in fired it right back up.

[DrPhoton]

600 watt has higher effeciency than the 1000 watt. Try get a 600 watt ballast imo.

[DrPhoton]

600w HPS has an efficiency of about 1.7-1.8 umol per watt. Providing around 1100 umols in total light output. 1000w single ended has about 1.3-1.4umol per watt efficiency, providing about 1300umols of total light output. Quite a difference. 1000w double ended, has around 1.7umol per watt, with the highest total output of around 1700umols.

Check some of my articles out for some further information.

[Toripony]

Wow, Dan, 200 extra umol for extra 400 watts of power?! That really doesn't seem worth it to me. Thanks for your expertise there... I'm checking out your articles on this now.

[DrPhoton]

My pleasure, yes 600 watt efficiency is very good.

[Toripony]

Question #4: I keep reading that lamps should not be refired less than 5 minutes after shutoff. What do you do about quick little power outages? We get a lot of those here in the winter.

[Chefbjy]

If you have a dimmable ballast you can run 600watt bulb at 600 watts np. You can run 1000 but with that space 600 will be plenty. I prefer to spendthe extra buck on a bulb it's well worth it. Hortilux would be my suggestion but any brand will do. I have a timer from Wal-Mart it's not the cheap one but it's not very pricey either works fine.

[DrPhoton]

You would need to refer to manufacturers recommendations/instructions to assure that the product is compatible with multiple bulb wattages.

[Toripony]

I've seen the ballasts for sale with settings like 400, 600, 1000, but this one just has 50%, 75%, 100%, none of which equals 600 W. Didn't want to take chances until I asked you guys.

[DrPhoton]

Yes if it has % values, it most likely not ideal for multiple wattage bulbs. However, even if the ballast says the specific wattage, this still does not mean its compatiable. So i refer to the manufacturers for confirmation.

[Insight]

Question #4: I keep reading that lamps should not be refired less than 5 minutes after shutoff. What do you do about quick little power outages? We get a lot of those here in the winter.

the solid state ballasts have protection for that scenario....it won't turn it back on until the bulb cools down.

[Toripony]

Well, I have the HPS installed now... 600 watt. The only bulb I have requires a magnetic ballast so that's what I'm using for now. I read that it's less efficient. I also acquired a dimmable digital ballast to use once I buy a new bulb. Now I've come upon a couple of new questions:

Back to question #4 above, Insight, you said the "solid state ballasts have protection"... does that mean the magnetic one doesn't?

New question #5, DrPhoton, you said the 600 watt HPS provides about 1100 umol. In your efficiency and distance articles you say the best range for flowering is 500-700 umol. So I need to lose ~500 umol?? Is that lost in fixture-to-canopy distance? What am I not understanding here? What distance do you recommend? I have it at 19" and for now it's only lighting one flowering plant that's about 2x2 feet across.

And question #6... The 600 watts of HPS light looks dimmer than the 432 watts of T5... is that just to my human eyes or is something wrong with this bulb or ballast? Are my eyes not seeing all of the light?

Thanks for the help, all!

[DrPhoton]

The 1100umol figure is a photon flux value (PPF), which is different from a canopy measurement which is a photon density value (PPFD).

You cannot interchange the two, as they represent two different things and do not hold the same value. Each light source, especially with different reflectors will have slightly different height requirements. However i would look at the GWE on HPS lights where nebula provides good information on ideal approximate heights. To follow my Using Light Efficiently guidelines, requires a light meter, such as a LUX or PAR meter.

Yes, fluorescent lights produce a lot of energy in the green wavelegnths, which the human eye has a higher sensitivity for. This is the reason for photometry systems, as it applies to what our eyes see compared to what light energy is actually being produced.

Have a look at my article on light metric systems to learn more.

[Toripony]

Aaah, ok, my confusion, as expected. I guess I should have read Light Metric Systems first but will need to rest my brain a bit now, lol.
Yea, Nebula has a great chart there, that's how I got my 19" starting point.
THANKS, again!

[DrPhoton]

No problem, no question is silly. So if you want any further help, ask away.

[Insight]

Toripony ..Back to question #4 above, Insight, you said the "solid state ballasts have protection"... does that mean the magnetic one doesn't?

As far as I know....the magnetic ballasts do NOT have protection. I have used one and did not run into any problems....but don't know if I ever lost power and it came back on quickly.