T8s, instant start, and e-ballasts - looking for enlightment

Hi James,

>Having read what has been written on this topic I am thoroughly confused  
>(which is not hard to do however). I am aware that this topic has been 
>beaten to death on the list but I hoping all you experts out there will 
>indulge me because I remain in the dark in this area.
Unfortunately we in Australia dont have the same freedom to products as they
seem to elsewhere in the world. However we do have access to simular
products, (some may even be better).

>My problem is that here in Australia nearly all flouro tubes sold happen 
>to be T8 size and rated at 18W, 36W etc. It is nearly impossible to find 
>a T12 bulb though I have seen a few at specialized lighting places.
I cant see why you would want a T12 in the first place. The reason most
tubes are T8s in Oz is it is the Aust Standard. T8s are more efficient and
cheaper to buy than T12s and provide the same sort of light output. 

>1) Do the 18W and 36W power ratings mean that these tubes are not the 
>high efficieny tubes referred to on the list rated at 17W and 32W. If 
>these tubes are not the high efficiency tubes then what are they?
Im not sure about the answer to this question but wattage does not determine
a good or bad tube. It is the characteristics of the tube that determine its
effectiveness within the application you require it for, eg. colour temp,
what lumens does the tube have? A good plant tube here in Oz is the NEC HG.
The 4ft tubes are 37 watts and have great characteristics for growing
plants, I dont have the specs with me here. They are also very well priced
when comparing them to Tritons and the like. I usually buy them from a
lighting distributor (they have to order them) for around $10.

>2) I've read in the archives that only e-ballasts can drives T8s 
>properly. I doubt that this is the case here in Australia as it is near 
>impossible to find e-ballasts and the only ballasts available are these 
>big heavy things which don't look very electronic to me. (But then again 
>- - I've never seen an electronic ballast.) Am I right in believing that  
>magnetic ballasts can drive T8's (at least in Australia)?
I dont know if this is true esp considering the majority of house hold T8s
are driven by magnetic ballasts. There are e ballasts around, you just need
to find them. They are not cheap here however and you may consider getting
one over the Net (providing it is 240 volts). I got mine from a place here
in Adelaide called Nelson Lights. They manufacture these ballasts and sell
them to HPM. HPM is huge here in Oz so you should be able to access them.
The ballasts can run up to two 40watt tubes and has closed circuits. I warn
you though they are not cheap.

>3) And finally I heard someone mention that e-ballasts designed for a 
>4' tube shouldn't be used to drive 2' tubes even thought they might work. 
>Is this so, and why?
Im not sure on this either but there is no mention of limitations on the
ballasts I have except for the wattage of tubes that can be used.

If you have any further probs yell out privately if you like.

Andrew Hamilton