Went to my local retailer and they had small ones for £10 no big ones. Wouldnt want to spend silly money on a couple as its not majorly important. White card you say is recommended? would that give a noticable different? what about a white card with a shiney foil on 1 side? like chinese takeaway lids.sheet of white card, with a slight bend in it should do the trick, or some foil curved, but a white surface is better.
You can get reflectors for £6-10 each, from any LFS/online retailer.
Plain white reflects better than a mirrored surface, white surface reflect all wave lengths of light.
Well done that should be easier for me to get over a long 42" peice of card. Will definatly do that. Maybe i can find some on the roadside or in a skip so its a complete free d.i.y jobby lol.I think the slickest DIY I have seen for a reflector was a piece of white rain gutter just mounted behind the bulb.
Yes, Because the reflectors unique shape ensures most of the light enters the tank, whereas a lid wouldn't do as good a job.