DIY lighting VS new light hood

[JProx]

some misc. stuff i forgot to mention with my last post, but you should already know this, its all common sense stuff.

you will need to keep the bulb covered and protected from the water, most commerical units and diy'ers use a glass tank top, this is not optional, and is pretty much mandatory. the reason for this is MH bulbs get very hot, and if a few drops of water touch the glass of the bulb, it will shatter and could start a fire, electrocute people / tank inhabitints.

don't exceed the wattage of the ballast. if the ballast is rated for 100watts don't use a 250watt bulb. also use a cord (to supply power from the electrical socket to the ballast) that is rated to handle the current draw, ask someone at home depot for recommendations. also when you finally get everything mounted and wired, and when you turn the unit on for the first time, don't be alarmed if the bulb takes 20mins to fully ignite its very normal for that happen.

 

[StrongBad]

Again, some great info and just what I was looking for. I realized in reading one of my last posts that I did not include a link with my last question.
Are these ballasts any good. THey are pretty cheap compared to most I have seen.
http://www.1000bulbs.com/category.php?category=26

 

[StrongBad]

is this useable?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=58144&item=7528414300&rd=1#ebayphotohosting

 

[greenmaji]

this is my best guess in explaining the price difference ok.....
these ballasts are not being advertised to be used for a fish tank.... they are being advertised as being MH ballasts wich are used in commersial lighting applications.. the price differince is from the fact that the ballasts are not worth as much to commersial lighting consumers.. actually they could also be selling them to the companies that make pre-maid units and they wouldnt be able to make a living if they didnt get them for alot less then they sell them for.. just a thought..

 

[greenmaji]

the ebay item is a 227 volt fixture.. the ballast would need rewired to be able to use it in your house (120 or 240 volt) if Im not mistaking....? anyone else think this is a problem JProx?

 

[JProx]

well some MH ballasts can take 120/227/300+ volts of input electricity, while others can only take 120. if the fixture was built to use 227v it should be able to handle and properly function on 120volts. so if you luck into a fixture that uses 227 it should run just fine on 120, with out any special cords, sockets, etc.

i would stay away from ebay if possible, you are relying on a person who might not know what they have, and might have listed half truths, or listed broken items and at 22bucks to ship i wouldn't take the risk, unless their listing was alot more detailed. just my thinking on this... i did buy an arc welder off of ebay a few yrs back, and when i got it, it turned out be a Chinese made - hunk of crap, all the accessories that were included were really poor quality, the welding hammer snapped after 2mins of work and the directions that were included read like they paid some one 2bucks to do the translation from Chinese to english. Sorry for the rant... back to MH stuff...

Green - i would say your partially right about the cost difference, the other side of the coin of pricing has to do with the actually ballast design. just like fluorescent fixtures there are electronic, and magnetic ballasts that both work pretty well but cost a bit more to build. the major difference is that magnetic units tend to die within a few yrs of use, severely shorten bulb life, and can be prone to generating more heat but they do tend to be cheaper than the electric design. i have read some artciles a few wks back that states an electronic ballast can extend the life of the bulb to 18 - 24months with out any loss of light intensity/spectrum. as a comparison Magnetic ballasts usually will keep a bulb operating properly for 12-18months.

however when your picking a design to use, you should weigh your pro's and con's. Is the cheaper magnetic ballast a better deal? sure it might lower the life of the bulb, but you will have to change the bulbs every 12 - 18 months anyway to maintain intensity and spectrum coverage. and if the difference in price is severe you might be able to buy 2 magnetic ballasts for the price of 1 electronic unit, and thus lower your repair costs later. ballasts will fail eventually anyway, no ballast will live a 30+ yr life, the longest unit i ever had was a 22 yr Hi-pressure sodium lamp for comparison. so this issue does need some thought, i usually just go with electronic units to be on the safe side and squeeze as much life out 1 bulb as possible, but some people do like to live dangerously and travel cheap.

 

[StrongBad]

The frequency would need to be 60HZ though no matter what voltage right? FOr instance a 220 volt 50hz MH fixture would not be compatible.

 

[JProx]

i hate to say this again but some fixtures can operate on 50hz, some can't. its up to the manufactor weather it will work on a different frequency correctly. my gut feeling is that the ballast will work fine, however i would urge you to find a ballast that is known to work with what you have 120v/60hz. and you can double check with the company your buying from after you found your preferred unit.

 

[greenmaji]

It just seems from the wiring diagrams Ive seen you can wire the ballast for different voltages..