Metal Halide's

[xxBarneyxx]

Looking on ebay there are some good deals on "floodlight" MH units. I was just wondering though if these are suitable for using on a marine tank and if there is anything I should be looking out for.

One thing I did think of is there is probably different bulb types and some bulb fittings might not have bulbs in the right colour spectrum?

For example this to me looks like a really good deal but it looks like the fittings are different to most of the proper marine ones I have seen. Also I dont know if this comes with everything you need or not?
http/cgi.ebay.co.uk/5-x-250W-Metal-Halid...1QQcmdZViewItem

 

[michaelwgroves]

I looked at getting non aquarium metal halides off eBay, but then just by luck found pair of Arcadia 250W Metal Halides on the classifieds for only £100. Bargain..........
Any way, what I did discover is there are many bulb fittings, whilst bulbs are plentiful for these units, you might struggle to get the correct kelvin.
Therefore make sure you get FC2 on 250W and Rx7s on 150W, as these are the standard fittings for aquariums.
There is also something about the ballast which affects the light intensity, you need to research this.

Looking at your tank I would have thought 250W would be too powerful, 150W is suitable for most tanks up to 60cm deep?

Check out the classifieds, there are some bargains here, but you will need to be quick........


http/www.aquarist-classifieds.co.uk/php/...al%20Halide.php

 

[xxBarneyxx]

Thanks for the info. Its not for my current tank FW, but for a new 5ftX2ftX2ft one I'm setting up.

 

[SkiFletch]

Thanks for the info. Its not for my current tank FW, but for a new 5ftX2ftX2ft one I'm setting up.

250watters would be on the high-side, but not drastically so. Do you have braces atop that tank holding the long sides together? Remember, if you place a halide directly over the brace you see a bigtime shadow effect in the water.

And Michael hit the nail on the head with the socket types. You can totally use the cheap fixtures. Thats what AK77 is doing. 30quid floodlight, replaced the bulb with an aquarium spectra and voila

 

[pengy666]

If only it was that easy eh?

Looked into this a good month or so ago,

Only way to describe it, is a false econemy?

Here is a bit of info given to me when I asked about industrial MH lighting

A word of caution: Cheaper 'Industrial' lighting units or MH floodlights commonly come with what's known as an MH/MV ballast ( Metal Halide/ Mercury Vapour ). These should never be used to light MH Lamps for aquarium use, as they are not efficient enough at controlling the voltage requirements of the lamps. The light emitted can vary massively in terms of spectral output with large amounts of UV combined as a consequence, which can cause severe damage to livestock etc.. Please ensure when buying ballasts that were not specifically designed for aquarium use, that they are of the MH/SO (Metal Halide/ High Pressure Sodium) variety and not MH/MV

This is his website


Lighting

 

[michaelwgroves]

If only it was that easy eh?

Looked into this a good month or so ago,

Only way to describe it, is a false econemy?

Can you elaberate on that?

 

[pengy666]

sorry I was looking for info I got just to quote correctly

I have edited now

 

[michaelwgroves]

If only it was that easy eh?

Looked into this a good month or so ago,

Only way to describe it, is a false econemy?

Here is a bit of info given to me when I asked about industrial MH lighting

A word of caution: Cheaper 'Industrial' lighting units or MH floodlights commonly come with what's known as an MH/MV ballast ( Metal Halide/ Mercury Vapour ). These should never be used to light MH Lamps for aquarium use, as they are not efficient enough at controlling the voltage requirements of the lamps. The light emitted can vary massively in terms of spectral output with large amounts of UV combined as a consequence, which can cause severe damage to livestock etc.. Please ensure when buying ballasts that were not specifically designed for aquarium use, that they are of the MH/SO (Metal Halide/ High Pressure Sodium) variety and not MH/MV

This is his website


Lighting

Top answer, I knew there was something about the commercial ballast, but I never knew what. This thread nails it........

 

[pengy666]

Yeah, I just decided rather than save few quid it aint worth it! it could cost more than what a new set of top brand MH's can cost in live stock!

I spent best part of £200 on my T5's but I didnt wanna lose my lid or hang lights from wall/ceiling and I think my lighting really does a fantastic job for T5's!

Pictures dont do the light justice (obviously )

Also I reckon someone wants to warn AK77 if he is using cheap MH'sbut I dont wanna offend him??

 

[AK77]

Hmm that's interesting reading.

Thanks for the heads up Pengy

My lights are made by Whitecroft Lighting and just checking the manual, can support HQI/CDM-TD/SON-TS lamps (SON being the High Pressure Sodium Lamps) so I would imagine the ballasts are of the MH/SO variety. Added to that I've had my xenia in the tank for well over a week now and they are flourishing.

Personally, I would have thought Barney could get away with 3 lamps mounted equally above the tank. I'd contact the vendor first though and enquire as to the type of ballasts before purchasing.

 

[SkiFletch]

The light emitted can vary massively in terms of spectral output with large amounts of UV combined as a consequence,

And clearly the writer of that oppinion does not know the details of the construction of aquarium bulbs. All aquarium metal halide lamps have two sets of glass. The inner nipple contains the metal halides which are burned to create the desired spectra of light. This inner nipple emits UV light even in proper operation along with photosynthetically active wavelengths. Then the outer glass casing is a UV shield that scrubs out the harmful UV wavelengths and prevents them from getting into the tank. So even if an improper ballast causing improper voltage to the bulb caused the nipple to emit more UV than normal, the outer shield would remove it.

My lights are made by Whitecroft Lighting and just checking the manual, can support HQI/CDM-TD/SON-TS lamps (SON being the High Pressure Sodium Lamps) so I would imagine the ballasts are of the MH/SO variety.

They probably are. The MH/SO variety are very common, as are the MH/MV variety. USUALLY the packaging or display of these units in a hardware store will say somewhere that the fixture can support mercury vapor bulbs and often they even say that they're designed for mercury vapor, not metal halide