Custom hood, part 1

fraggle_a

fraggle_a

Member
Alright!.
So begins the home made hood for my 40 Gallon tank.
I scoped out the wood. Im going to use some ply and 1x2 for the hood. The 1x2s will be the base and the Ply will over hang to cover the nasty black plastic trim around the tank.
The 1x2s will also server to reinforce the top, and as mount points for hardware.
After that, the insde will get a coat of sealer, then a sheet of polished aluminium will be attahced as the reflector, Thin stips will be doubled over to make hardware to hold the MH fixture.
So, what have I actualy accomplished so far?.
Well, I have through testing established that a $21 security light from Home Depot has the kick to start a 150Watt Metal Halide bulb and run it. I also established that I have to spend some time removing the guts from the lamp housing and also remove the photosensitive diode that turns the light on and off.
A very quick look at the Diode and housing suggests it sits in the circuit between the Ballast and Bulb, but Ill find that out later.
The $25 MH Bulb was returned to Home Depot after the test and a Medium size Ceramic Mougle was purchased for $5 to take the MH Bulb Im targeting.
A simple Powertool replacement cord also seems to work fantasticaly as the power chord and ran a wallet breaking $6.
IT seems so far the single most exspensive part of this project could end up being the plexiglass (or glass) insert to stop the saltwater from splashing onto the lights, LEDs and PCs.
:footnote:
A wizard idea was to use some 12v computer fans as a cooling solutoion, which also leads nicely onto creating my own "Nightlight" system.
 
jakebtc

jakebtc

Member
hey fraggle what brand or model of light fixture you using for this may I ask
:thinking:
or if you can post a pic
 
fraggle_a

fraggle_a

Member
Its a medium sized Mercury Vapour security light.. Its almost the cheapest security light Home Depot does. Lowes does exactly the same model for about the same price too. I belive its by Lithonia.
Heres the lamp with the MH bulb in it.
(its a BIG bulb, i got a medium mogle so i can use the smaller bulbs later)
 
fraggle_a

fraggle_a

Member
Okay!
I stripped the guts from the lamp.
The Ballast is a simple magentic type as far as I can tell, Its kinda heavy and seems to get warm.
The bulb gets hotter than english man on a spanish beach mid summer!!.
Gonna need some seriouse airflow over it to keep things cool.
I managed to bypass the photosensitive switch no problem. The switch polls between the black and red wires. So thats a simple fix. But it also gives me a nice option to add a manual switch. :)
I have a picture of the ballast, cables and bulb but Ill post that later on my "Projects" page on my web site.
Tommorow Im going to start working on the wood part of the project and get the basic canopy setup.
 
tropills

tropills

Member
Originally Posted by Fraggle_a
Its a medium sized Mercury Vapour security light.. Its almost the cheapest security light Home Depot does. Lowes does exactly the same model for about the same price too. I belive its by Lithonia.
Heres the lamp with the MH bulb in it.
(its a BIG bulb, i got a medium mogle so i can use the smaller bulbs later)

Don't do it .. The ballest won't hold , and it will fry the bulb. trust me been here done that.
But if you want to try it go ahead just giving you my 2 cents on somthing I have already tryed.
 
fraggle_a

fraggle_a

Member
You have to get the right kind of MH bulb.
If you put a bulb that wants to be Pulse started into a magentic ballast, its gonna die fast.
 
j-bird

j-bird

Member
Originally Posted by tropills
Don't do it .. The ballest won't hold , and it will fry the bulb. trust me been here done that.
But if you want to try it go ahead just giving you my 2 cents on somthing I have already tryed.


I guarantee you are not getting full spectrum or intensity from MH bulb in that fixture. Just because the bulb lights up, does not meen it is doing what you need it to do, the bulb will fry after a couple of weeks. Not trying to rain on your parade, and do whatever you like. But they do not make MH ballasts for no reason,...there is a VERY good reason to have one, if it were this easy, don't you think everybody would be doing this.
Word of Advice....Make sure your home insurance (fire) is paid!!!!!
 
fraggle_a

fraggle_a

Member
Actualy, Im ordering my MH bulb from online. A store in California.
Its a bulb to run in a Magnetic / electronic ballast.
Yes, I know they make MH ballasts. But doesnt it strike you as strange how a MH ballast is exactly the same construction as a MV capabale ballsat?. (its a very simple design). Infact, if you check deeper, they are even advertised in places as Metal Halide and Mercury Vapour Ballasts. The only thing you have to be careful of it the differance betweek the "Pulse" starters and the Magetic/Electronic types.
The Pulse starters will definatly fry a non-pulse capable MH lamp because the lamp doesnt have the components to shut off the 500+ Watt kick from the Ballast. If that kick continues for long, its going to cause trouble. Same as putting a Pulse Start bulb into a magentic ballast. Your going to have problems there too.
Metal Halide bulbs are called metal halide because the term "Mercury Vapour with Metal Halide" is too long. A Metal Halide bulb is a MV with an extra component. Once the MV is started the heat generated activates the Halides and produces a reaction with the Mercury. Once the reaction begins, the light burns brighter and the Halides can sustain the mercury vapour at a lower current. The Halides only produce a limmited specrum themselves. A stright MH bulb from HD is exactly what it says. MV+MH elements.
Aquarium bulbs contain more than just MV and MH. Argon is one, and there are a number of other elements found in the aquarium Bulbs you can also find in Flourecents. I forget the name of one, but the principle behind it is simple. At a normal temperature, it does very little. Once heat and pressure are applied it generates a blue/violet spectrum, the spectrum, is a ways into the blue so we can bearly see it, but you can see it as it refracts on the waters surface.
The cahnges the gasses and elements have on the light geneated is exatly the same idea behind spectroscopy
Adding these extra ingreadients is costly and difficult to complish, hence the price differance between a simple and uncomplicated MV+MH (around 5000k) and a 20K.
 
jakebtc

jakebtc

Member
Originally Posted by J-Bird

I guarantee you are not getting full spectrum or intensity from MH bulb in that fixture. Just because the bulb lights up, does not meen it is doing what you need it to do, the bulb will fry after a couple of weeks. Not trying to rain on your parade, and do whatever you like. But they do not make MH ballasts for no reason,...there is a VERY good reason to have one, if it were this easy, don't you think everybody would be doing this.
Word of Advice....Make sure your home insurance (fire) is paid!!!!!

no everyone wouldn't do this for the simple fact hardly anyone does research that's why most people go out and spend 900$ on a fixture rather then a diy
because they are not mechanicly inclined wich really doesnt take much or they just don't have a problem blowing money
everyone assumes being in this hobby has to cost a ton of money so when it comes to lighting they go with the branded "aquariumm lighting"
what he is doing will work fine so long as the ballast and light "match" and he's done his research because he knows that already
 
fraggle_a

fraggle_a

Member
Metal Halide and Mercury Vapour:
From Wikipedia, the free encyclopedia
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A halide is a binary compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, iodide, or astatide compound. Many salts are halides. All Group 1 metals form halides with the halogens and they are white solids.
Metal halides are used in high-intensity discharge lamps called metal halide lamps, such as those used in modern street lights. These are more energy-efficient than mercury-vapor lamps, and have much better colour rendition than orange high-pressure sodium lamps. Metal halide lamps are also commonly used in greenhouses or in rainy climates to supplement natural sunlight.
 
tropills

tropills

Member
fraggle--- Did a search on google, you can run a merc.vapor bulb on a metal halide ballet but you can't run a halide bulb on a merc. vapor if if they look the same and are the same wattage. just to let you know . not trying to be mean but please make sure you are 100% right would hate to see you have a fire.
 
tropills

tropills

Member
Originally Posted by crustymonk
what the heck is MH and MV?

Metal Halide, Mercury Vapor types of lighting
 
shrmnator

shrmnator

Member
that would make an excellent refugium light fraggle but may not be good enough for the display tank causing pest algae growth. then again i would like to continue reading your posts on it as this would be a much cheaper solution. but with it being such a cheaper solution it would be widely used already. if you become dis-satisfied with it make it a fuge light and it will grow algaes like weeds!
 
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