High Pressure Sodium Light?

[Octoberfest]

Ok, a few years back my brother was somewhat of a pot head. He was growing his own in his basement. Well I'm happy to say he stopped doing that a few years back and is a much better person now (more social, just all around more fun to be around).

Ok, having said that he said he has a bunch of lights left that are just collecting dust. Only thing is that they are High Pressure Sodium. I know that they will give off a yellow tint in the tank but is there anything short of the reflectors that I can use? Is there anything that can be done with these to make them suitable for a reef tank?

[jenglish]

from what I have heard these are just algae machines. I think they were tried pretty extensively in the earlier days of reefing due to the fact that they really are quite bright. I have not heard of someone succesfully using them for a reef. But I have never tried myself.

[greenmonkey51]

Wrong color temperature. Plus they most likely use more energy than most common lights.

[Octoberfest]

Ok, what if the bulbs were changed out, I mean are the socket and ballasts compatible?

[john rochon]

no, they cannot be used. there to yellow and no reflector or actinics can fix that.

[Octoberfest]

so the entire system from the ballast, chord, socket, reflector can not be used. No mods can be done?

[landlord]

If you knew what type of HPS lights they were there might be a possiblilty. Some of the ones sold by various Garden Supply houses had interchangeable ballasts I believe that would allow you to use High Pressure Sodium (during vegetative growth) and then would allow a switch to use MH (during the flowering phase). I imagine that without knowing exactly what you've got it would be risky to try anything.

[Octoberfest]

ok well when I got to look at it I'll find out

[tatkinson]

Whoa, slow down... everything isn't trash. The fixtures, sockets, cords, etc could be perfectly fine. The HPS ballasts can (sometimes) be modified to drive MH lamps depending on the HPS ballast but it's not a straight forward tit-for-tat kind of thing. A couple of factors make doing so impractical for our application. The first is the fact that our high K bulbs cost about 800% more than a regular MH bulb so if incorrect tolerances shorten the bulb life by even 5% it's not worth it and second the cost of ignitors and capacitors for a retrofit relative to the cost of a new ballast is negligible.

Ballasts can be had cheaply from various online retailers and generally there is no need to go with those specific to aquaria use. If the ballasts are enclosed in your fixtures you simply need to change out the ballasts with a MH ballast (if going with magnetic, the ballast should come with ignitor and capacitor). If the ballasts on your fixtures are external then you may want to consider the ice-cap type pre-packaged units but, again, you don't have to.

I assume your current fixtures have screw-in bulbs with a base that looks similar to household bulbs only bigger- this is a "Mogul" base. If it is the same size as a household bulb it is a "medium" base. If you wish to keep this set-up the only thing you have to replace is the ballast everything else is fine (socket etc). Just put in a MH bulb and you're good to go. An aside, if you wanted to upgrade wattage now would be the time to do so since a 400W ballast is not much more than a 150W. Just make sure you have enough clearance in the fixture for the bigger bulbs and going from 150 to 400 may be a bit extreme. Also make sure new bulbs match the burning position of your fixture. While some bulbs are "U" or universal, others require a specific burning position - vertical, horizontal etc and generally allow for +or- 45%. Not playing by the bulbs rules will almost always dramatically decrease life.

When buying a new ballast just make sure the ANSI #s for the lamp you want to use and ballast match. ie a M98 ballast should be used to drive a M98 lamp. All the different numbers can be confusing so just do your homework and you'll be ok. Ballasts can be had online for well under $100.00 but I'd make sure I got one from a respected manufacturer (philips, sylvania, advance, venture, etc) because usually a cheap $ ballast is a cheap ballast.

If your fixtures have the lamp in a horizontal position you could change the socket to a double ended and place it in the middle of the reflector and run HQI bulbs. These bulbs require a pulse start ballast (sometimes more $ sometimes less $). There are some advantages to going this way. If you're buying top shelf bulbs the CRI on a pulse start lamp is going to be significantly higher than a regular lamp and generally the higher the K the more unstable the CRI so, in my opinion pulse start is more advantageous to our application than most others. PS also supposedly consumes less power. If you were running a parking lot full of fixtures a possible plus but not really much of a concern for us. Pulse start also generally equals faster start-up and restrike as well as higher lumen output both initially and throughout the life of the bulb and a much higher CRI. There is debate over the merits of pulse start so if it's a way you may want to go do some checking and get all the info. You can not run pulse start lamps on a non pulse-start ballast and PS lamps can be more difficult to find, not so much in the double ended high K but definitely in the high K Med and Mogul bases. Conventional wisdom says that you can't run regular lamps on a PS ballast. I can not see any reasons other than theoretical as to why not and have done so on several occasions when a PS lamp was not available with no ill effects to either lamp or ballast.. the only possibility I could see, which is theoretical, would be diminished bulb life. In my personal real-world experience, which is in no way scientific, this has not been the case

Sorry for the length. Hope the info helps a little...... Wish I had some old HPS grows to convert.

Good Luck,
-T-

[Octoberfest]

VERY helpful thanks. When I get it I'll figure out what it is and go from there. Never know, maybe it will work.

[Ehgemus]

Originally posted by Octoberfest
so the entire system from the ballast, chord, socket, reflector can not be used. No mods can be done?

Yes the ballast, sockets and cords can be used, just buy the reef bulb. And yes I have used the High Pressure Sodium ballast before for reef lighting.

[widmer]

Originally posted by greenmonkey51
Wrong color temperature. Plus they most likely use more energy than most common lights.

One out of Two points correct. Wrong color temperature, yes. But they are one of the most efficient lights out there, thus the reason that they're the standard light used over most highways.

[Michael]

no dont use them, they are basically street lights, totally unsuitible for reefs