Trying to make my planted tank more efficient

Hi there,
I have 2 questions, I am currently in search to make some things more efficient in my 40L aquarium for plants to thrive.
1. I am busy to try to get some sort of a reflector going. At the moment I only have a 10W fluorescent light in my aquarium and I'm trying to make a DIY reflector. Online people have a lot of different opinions on what to use. Most people seem to think that aluminium tin foil and white paint are the best reflecting materials. Some people argue that tin foil is more of a diffuser than a reflector and I really can't see why it won't be a good reflector.
I have done some sketches to determine the best angles for the reflector to make best use of the light.
Can someone also tell me how much more light can one get out of using a reflector in the most efficient way possible.
Some people say it is up to 100% more which I think can't be possible as the light coming off the reflector is only a reflection and not the direct light.
I bought a can of gloss white spray paint today to see if I spray the whole lid inside if that will make a difference as the lid is currently black and a lot of the light is very much only absorbed at the moment.
2. I don't have any aquarium planting soil in my tank as I never knew that I would eventually switch over to real plants. I really don't want to take the gravel out to put in soil, because the proper aquarium soil is very expensive and then it's such a big job to remove it. Would it be beneficial for the plants if I add some fertilizer tabs in the gravel? I am using Seachem Flourish, Excel as well as Trace elements at the moment but I just want something to reach the roots of my plants.
The attached pic is basically what it looks like at the moment

 

I'm using a pic pipe (rain gutter pipe) which I cut in half, and it made a huge difference in lighting in my tank. I'm actually tempted to spray the inside of the pic pipe chrome to see if it will make any difference as the pipe is white atm.

 

You don't have to use aquaruim soil which is expensive like u said I use organic potting soil from my local nusery which is less than 50 rand and I have seen the difference in my plants as most plants draw their nutrinents through their roots so that would be something you should look into

 

Your gravel size is too big to be able to do some serious planting. Root tab doesnt help if gravel is too big. I afraid you have to start all over again