I copied what I wrote from another thread. It seems I'm seeing a lot of foil lately...
One thing you could do to improve your light is to do the following...
When you get time, etc. Get some cheap flat white paint - can or spray.
Paint the pots white - it reflects better than foil.
If you deside to stay with the foil do this:
Turn your foil around to make the flat side show out. It reflect better than the shinny side. I read this info in The Cannibis Bible.

Good luck!