My set up

Flowering room is not going to be light proof it does not need to

You have a decent space to work with.. are you planning on going perpetual? Also how is temp managment? Outside temps during winter? Outside temps during summer? Do you have a main venting line for hot air and fresh air? I still think you should get some poly plastic and divide a space for your needs it will also light proof your room and will be easier to vent out heat.

You want to be sure it only gets light for 12/12 in flower. Light leaks screw them up. Video works now.

The vegging box will be moved behind the mylar put up on the beams so no light will get to the budding plants

I might not be seeing things how they are but.. if you just have mylar on the sides then light will still get to the flowering plants. (Light is bendable!) Has to be totally black during dark. Pitch black.

Well i will just put the veggin box down into my flat, all these plants are going to be putt into budding at the same time anyway

If you use both spaces you can go perpetual.

Good point, i will focus on that another day but for now do you think i could just put a sheet of mylar over the cfl laying on top of the box and tap it to the sides of the box so it can stick on or does the mylar have to be on a flat surface?

Here's an update for everyone
First picture, how well the candy kush has grown overnight
Second picture, inside of the setup
Third picture,how bright it is now I have put a sheet of cardboard layered with mylar on top.

Just remember in a small cup like that the roots will fill it up quick.

I know buddy wen't and brought some big pots today, got 50l of coco soil being delivered hopefully on friday

in engineering terms you want to max out the amount of light that gets back down to your plants so avoid just a flat surface get some plywood cut 7 equal strips and fasten togeather with metal strips and rivets or something similar and then cover the underside of it in mylar and there you have it or do what i did and just pay a little money for something you know will be made to a certain standard