Re: Again on electronic ballasts.

> Problem is the unusual wattage of lamps (30 watts each - they cover completly
> my tank lenght), and Osram technical support told me that their model QT2x24
> dimensioned for 2 lamps 0f 24 watts is correct also for my 30 watts lamp.
> I am a little suspicious, being also expensive, to buy something that 
> doesn't
> work properly, thus I ask you if somebody may help me to decide to buy it.=
> Ciao  Ezio 

I would listen to them.  My experience with electronic ballasts is that
they can generally run a range of lamps.  Indeed, I've run 20 watt lamps
with a ballast spec'd for 40 watt lamps.  I don't suggest that you do this
(don't do it) but do offer it in support of the idea that e-ballasts will
can be quite tolerant.  Stay within the range that the mfrg suggests, and
you should be fine.  I think you will find that you get greatly enhanced
lifetime from your lamps and lower operating costs with the e-ballast. 

Light output might be lowered just a bit in the case you are describing, 
but probably only a few percent.  Lamp life should be outstanding.