downlights

[perthnovice]

i have a question for the electrically minded people on here you see i have made a nice hood for one of my aquariums but have hit a snag with the lighting i can buy a single tube flouro in a nice little case that i can fix to the inside top of my hood but for a 36in single tube is almost $90.00 and that just seems a bit much so my theory is to use 2 240volt halogen downlights these are just the price brand from k mart they have no transformer needed and have 50W GU10 globes.
but my problem is that when i went to my L.F.S. (local fish shop) they told me that they would use way too much power and would burn far too hot

so my question is will they draw too much power and will they burn too hot and if so can i simply change the globe and defeat both of these problems

thank you all in advance for your help and output and of course the information that i will get from here will only be passed onto my electrician oh and he might need a wiring diagram so that he can link both lights

[Don777]

Hi
I think what the LFS guy is saying the heat from the light could be an issue, fluros give off little heat, you put your hand in front of the little haligin globes , there hot... So you could end up with hot fish and no chips

Other wise cann't see an issue

Cheers Don

[dan76]

heat is the main problem you will face, those bulbs get to over 200 degrees during normal operation, was very surprised myself when i found out that.
also the colour temp of the bulbs might not be what you are looking for to grow plants etc.
as for the power useage 100w for 10hrs a day is 1 kilowatt and depending on where you live this is probably around 15c a day cost to run.

[pawnhead]

thank you all in advance for your help and output and of course the information that i will get from here will only be passed onto my electrician oh and he might need a wiring diagram so that he can link both lights:U
I'm sure that your sparky would know how to wire up some lights, but I'm also sure that it would cost you more than $90 to do it all. :wink:
I think it's OK for you to wire up your own plug in lights anyway. There was a heated debate about it here a while ago, and apparently there's no law against it.

If you want to save some money, build a box and buy a couple of standard batten holders. Use those new energy saving fluro globes in them. Cut a plug and lead off an old broken power appliance or something. (It needs an earth if the box is metal) Wire them up in parallel and not in series (ie full power to both of them, and not running through one and into the other):

http://i7.photobucket.com/albums/y266/holgerdanske/th_lights.jpg (http://i7.photobucket.com/albums/y266/holgerdanske/lights.jpg)

You could put a switch on it as well if you wanted. :2tsup:

edit: Earth the box if it's made of metal, and connect the earth where required in the batten holders. Make all of your connections in the actual batten holders. Don't use incandescent globes in them because of the heat, especially if it's a wooden box, but put some vent holes in the box anyway.
I'm sure someone is going to scream at me now. I'm just a clown so I'll take no responsibility for dodgy advice in this case :p. I'm just telling you what I might do, but a sparky may show up with some better (read safer) advice.

[patty]

Lighting companies puposely make Aquarium lamps for fish and reptilian lamps for reptiles tanks etc etc these lights are suppose to simulate the light levels in their natural environment and also aid in keeping algae growth and mould build up in the tank down and keeping any corals or plant life healthy! did the guy at the aquarium shop tell you this?

the lamps are expensive because they are not standard 4ft 36 w cool white /warm white /triphosphour lamps! on larger aquariums they have been known to use a combination of metal halide lamps together with fluros but that is on really large saltwater tanks

[patty]

Better than that go to an electrical wholeasler and buy a 36w 4ft bare batten fluro for about $16.00 you can buy light refraction kits that are used for pool tables and tanks which spread the light in a particular area and they screw intoi the fittings which are also round about 16$ sylvania do them pierlite do them then buy a 4 ft coral star or aquastar lamp these will cost about $30 bucks from memory and done!
Most flurs just sit on top of the glass top tank

[Smurf]

I've had fish for about 20 years and I'm also an electrician... :)

I'd forget the halogens. Simply too inefficient (lots of power and heat), don't last very long and the quality of light they produce isn't what you want in an aquarium - it will look yellow / brown as though the water is dirty.

Suitable lighting depends on the aquarium, where it is situated (natural light?) and what sort of fish and plants.

I have a simple setup for my mixed fish aquarium. It uses one standard "daylight" fluoro tube and one standard "warm white" fluoro tube. It's controlled by a dual timer (available at Bunnings).

Times I use are as follows:

For the warm white tube on between 07:30 - 08:30, 12:30-20:30, 22:30-23:30.

For the daylight tube on between 08:30 - 22:30.

This pattern mimicks, in a crude manner, the natural colour temperature and intensity shift in the light throughout the day.

I've had very good results with this setup and I know of one commercial fish breeder that did some trials after speaking to me about it (not sure how successful they were).

These tubes are real cheap too. I use electronic starters (available from any decent electrical wholesaler - they will happily sell these to the general public) to eliminate flicker when the tubes start (makes them last longer too). Also it means automatic shutdown of a failed tube. Electronic ballasts would be better but my equipment has been around quite a while.

You could build this quite easily yourself. Just get the required length of fluoro battens, build a box and wire them up. It is NOT illegal, at least in Tasmania (assume the other states are the same) for you to wire something up that is plugged in. DON'T do it if you don't know what you're doing however since all mains electricity can kill or start a fire.

How much light? 0.5 watts of fluorescent light per litre running for 12 hours a day will do if it's just a common mix of fish, plants etc. You'll need more light if you're serious about dense plants etc. My times are based each tube being 0.25 watts per litre since I'm using 2 tubes.

Other sensible options are metal halide and you could also use compact fluorescent or mercury vapour lamps. I'd stick with the fluoros if you're looking to save $ though since they are the cheapest option usually.

If you want to be as cheap as possible then just get a bare fluoro batten, ordinary daylight 6000K (not white 4000K or warm white 3000K) tubes from Bunnings etc, build a box and attach a flexible cord to the light (an extension with the socket end cut off will be fine for the cord - get someone who knows what they're doing to wire it if in any doubt though).

You could get the proper tubes if $ allow and that's what you want. I'm just using ordinary tubes though as I said and it's working fine. It wouldn't suit some plant types however - they need the proper aquarium tubes.

Tube lengths.

10 watt - 30 cm (12")
15 watt - 45 cm (18")
18/20 watt - 60cm (24")
30 watt - 90cm (36")
36/40 watt - 120cm (48")
58/65 watt - 150cm (60")

Use tubes to suit the tank dimensions. Number of tubes to get the required light intensity. You'll find the 18 and 36 watt at Bunnings etc. They might have some 15 and 30 watt tubes too but probably not the battens to suit. You'll have trouble getting anything but white (not what you want) in 10 watt. For 58 watt an electrical wholesaler is the go for both tubes and battens.

If you want maximum reliability then don't use 2 x 18 W battens wired in series (the common 2 x 18 watt type) and be aware that 10 W tubes can be quite a bit of trouble sometimes. Also get either electronic ballasts or at least electronic starters.

If you want the 30" tubes you mentioned then they are 30 watt (not 36 watt). Those battens aren't too common but any decent lighting shop can get them as can any electrical wholesaler (whether or not they WILL get them is another matter - shop around).

A quicker option might be to just get 36 watt battens, shorten them and swap the ballasts for 30 watt. I've done that a few times to make battens when the smaller sizes weren't in stock.

[patty]

Forget the 40W and 65W rapid start lamps smurf they are no longer available its only 36 and 58 w now mate! Someone says whats rapid start?

[dan76]

off topic a bit but today i opened up a circ fluoro tube (nec) that was a quad phosphor . claimed to be 18% brighter than a tri phosphor.
anyone seen these in action?

[memphis]

depends on the fish you keep, i have a 6ft marine tank with 800w of metal halide above it!.