250W MH Case Mod

[firegobies]

Here's a pic of the underside of the thing.. I hope that's what you meant.. sorry no pic of the MH on tank yet because there is no tank yet... nor is there a bulb yet... (still unhappy about this... grumble)

Thanks

As for the bulb i think you should be patient about it anyway Marine is patient hobby

[hoppinghippos]

damn ervine, you must be a DIY guru man! good stuff!

[Cedric]

Hi,

I think the DIY is really cool, however, I must agree with what Robe said. It doesn't matter whether you are blowing (very bad) or ###### air out (still bad) of the hood. Bottom line is you are still cooling the bulb and that will affect your colour temp as the bulb is not lit at the right temperature. Just my 2 cts worth, you have every right to reject what me and robe said.

[robe]

HI Ervine.

Your fan would be more effective blowing at the water directly rather than exhaust accumulated hot air inside the light. The heating of the water from MH lamps is caused by the radiation to a greater extent, infrared emitted from the arc and to some extent from the visible light waves hitting the tank.

It is also better to cool down the ballast to maintain the resistance of the coil. The hotter it gets the resistance increases leading to energy inefficiency.

Latent heat is released or absorbed as during the phase change of matter from liquid to vapor , vapor to liquid, solid to liqud or liquid to solid (example. Ice , steam)

[ervine]

HI Ervine.

Your fan would be more effective blowing at the water directly rather than exhaust accumulated hot air inside the light. The heating of the water from MH lamps is caused by the radiation to a greater extent, infrared emitted from the arc and to some extent from the visible light waves hitting the tank.

It is also better to cool down the ballast to maintain the resistance of the coil. The hotter it gets the resistance increases leading to energy inefficiency.

Latent heat is released or absorbed as during the phase change of matter from liquid to vapor , vapor to liquid, solid to liqud or liquid to solid (example. Ice , steam)

Yup there would be a fan blowing at the water surface as well.. as for the ballast, i'll just be leaving it as it is... see how things go, too lazy to drill another hole to cool the ballast (although I originally wanted to have it)

as for colour temp change due to the cooling effect, shrug, at most i turn off the fan... perhaps after I get my bulb I can run some simple checks on colour temp and temp with fan on and off... then can get some practical results..

Will keep you guys posted..

[lvcap]

very nice DIY

hope it works well and everything goes smoothly!!

cheers

[ah^siao]

nice diy.. hopes it works well on your tank too

[ervine]

AT LAST!!!!!!! AFTER MORE THAN A MONTH MY LIGHT IS UP AND RUNNING!!!

Check it out....

[ervine]

Here's a view of my new tank with the new light... quite er.. "massive" but hey it works!!

Oh and it doesn't heat up the water much... my temp now is the same as it was when I was using my PLs!!! (but those were very close to the water)

But this is considering I added that fan in the light casing as well as a permenant table fan blowing across the surface of the water...

[betaFISH]

Thats one really nice DIY setup..

[strat]

Nicec DIY!!

Hey you using PVC pipes to mount the MH?

[veeresh]

Bro

Superb DIY man..!!!! .. I notices from the picture that you do not use a chiller and you have coral in the your tank. Doesn't the light raise temperture ?

V

[DeepBlue]

how to raise temp??? look at the fan he built, supported by the huge table fan just beside the tank....keke..................

[ervine]

THanks guys... yah it's PVC pipes, 25mm ones connected and spray painted black (for aesthetic purpose only)

As mentioned, the water temp doesn't really budge much compared to when I was using PLs... probably due to both the table fan and fan inside the light casing..

BTW, the light casing fan is constantly pulling hot air out... so much so that I can touch the casing without it even feeling excessively hot..

The external ballast however is almost scorching to touch! (thus the reason why I used an external ballast.. that and the weight)

[ervine]

oh yah will probably try turning off the inbuilt fan see if the temp shoots up... but that will have to wait for a while till I get back home...