Grow medium for gorilla cookies auto

autoflowers are just plants. I'd strongly suggest resisting the misinformed idea that you should start an autoflower in a large pot. The difficulties and risks of doing so far out-weigh the perceptions that potting up somehow slows a plant down. I have potted up 300-400 some plants or more... not one has stopped growingn from "shock or stress." So, saying something over and over again doesn't make it true. Root zone will develop better if you pot up like every other plant. Watering will be easier. If you can't pot up without molesting the rootball like a chatholic priest left alone with a choir boy, then you should consider planting in its final pot. The negatives of trying to water a tiny plant in a huge put alone are worth avoiding like the plague. Exact constitution of a medium depends on the water capacity. Something that absorbs and retains more water needs ~50% perlite or similar for the best drainage and aeration properties. Something that holds less water per volume, like coco coir, only needs 33% of volume to be perlite or similar. Also, don't make 2 distinct layers. This is an over-sophistication that has more of a chance to cause oddities in your medium than any chance of being beficial. Over-thinking it / over-doing it. if you do add some perlite or vermiculite, etc, then expect to supplement with fertilization sooner than you would have in the past -- assuming familiarity with the products with past grows. as a 'new grower' i strongly suggest doing things in an orthodox way without sophistry involved. Once you have a good feel and confident you can grow anything seed to harvest without issues or headaches, then start trying new things, gimmicks and over-sophsticated setups... less likely to lie to yourself about whether or not they helped and better equipped to properly resolve such things with a baseline expectation of results to compare. Confirmation bias is a prevalent human foible.