50/50 soil - coco what's what's now, rule breaker

Nah, if its soil. You use soil ph. As light mix soil is mainly coco. But you treat it like soil imo. Not a stupid question at all. You will see any ph issues early (any early twisting in the leaves or other ph signs) you'll catch if its slightly out.

This depends on the fertilzier you use, not the medium it absorbs into. Since you are using soil, treat it like soil. Your soil comes with a pre-charge of nutes... you need to slowly supplement that over time as it gets used up. To limit leaching of that pre-charge, you don't want a lot of runoff, just enough to ensure you are getting entire volume wet with zero dry pockets occuring. 10% runoff or more is for a soilless context. when you provide 100% of the nutrients each irrigation, the 10% runoff prevents buildup. An equilibrium level will be reached and it'll be consistent unless you change the fertilizer formula. You'll need a little less perlite/similar drainage amendment to get an optimal gas:water mixture in the substrate. coco likely holds less water per volume than what it was mixed with - typical soil or sphagnum peat moss. Coco does not have any different feeding requirements. These are false conclusions of people that don't actually know what they are talking about. If it does cause any nutrition issues that is due to the fact coco, if unprocesseed, is fucking poisonous to plants, lol. It needs to be buffered with a solution similar to what you'll fertilize with in order to prevent and leaching or substitutions of what is freely available to the plants. (cation exchange sites... once at equilibrium, nothign is lossed or gained from the substrate in this regard) coco isn't magic. It has slightly different physical properties - namely it holds less water per volume, so you only need ~33% perlite or similar for a proper mix. Heavier options need 50% perlite. Do a weighted average for your substrate mix. ~40% will be sufficient. Coco isn't a bad option to use, but it comes with risks. Make sure you trust the brand. Shit coco will kill or severely sicken plants.

Lots of soil premixes utilize both. You're basically are making homemade light mix.

Coco is inert, and dries quicker, so you'll have to start supplementing feed sooner than in only soil and will need to water a little more regularly because it will dry faster. Coco does break down, but incredibly slowly, so that isn't something I'd worry too much about.

Never understood this style. I saw 90% of fails and only 10 % good results ( far from dream runs ) . I would go for coco if i need quantity. But i had good results in soil, mine tasted better ( personal view ;))) ) . So i stayed with soil always...