What is Reddit's opinion of Silver Reflective Mylar Film Sheets - Garden Greenhouse Covering Foil Sheets Set of 10 Pack | Mylar Roll for Grow Room Effectively Increase Plants Growth - 87 x 63 inch Space Emergency Blankets Fabric?

From 3.5 billion Reddit comments

These are awesome and cheap. I'd put it on the walls behind and to the sides: https://www.amazon.com/gp/product/B08DDJZC92/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

LED Lighting can be an economic pain in the wallet, but there are reasonable ( and lightweight) solutions such as Barrina lights. Just make sure to point them at the plants. They do not have to be horizontal.