There is a lot to be learnt still about growing with led lights. The problem is that your plants need a mixture of red and blue spectrum's in the light for maximum yield but with the LED lights on the market now days they just don't seem to put out the same lumens as your HID HPS or metal...
For sure.. most people think that a mirror is good but in turn it is the complete opposite. Like cowboylogic says they absorb the light and that is how we see ourselves in them.... Just use B&W polly.. the white side of course and it will serve as the best reflector out there.
it looks too late... i would just start fresh... remember when vegging the lights shouldn't be to high or they will stretch for the light. Keep em nice and low and you'll get short stalky strong plants with wicked bud formation...