Hi
@Uk420show aluminum paper does not work, you have to use white plasticized or mylar paper, you can find it at any DIY store for sale. The light from your light source when reflecting on the aluminum foil will create points of heat that will burn and damage your plant. if you are not going to have an air extractor, you should have an extra fan for air circulation and a dehumidifier because without an air extractor you will have high humidity during flowering. for grows without air extraction there is a good solution, 1 or 2 natural bags of CO2, you will find them for sale in any grow shop are a good help for those who plant without air circulation. good luck mate 👍🙏