Bat guano yes you can but no you shouldnt

You need to be experienced enough to use bat guano right. Not suggested. Also guano attracts flies and pests. Good luck!!

just to cut through a ton of noise on dry amendments, like bat guano (the upper tier amendments, often seabird derived/kelp derived/fecal matter and so on, like stuff that costs money and isnt just refuse) are only going to be valuable as an organic and naturally chelated version of nutrition; you are basically one step off from organic and naturally derived (non-synthetic or off-chirality) salts, which are basically the top price class...if it isn't this, then it is a phytohormone source. just putting poop in stuff is not always the answer, clearly.

Dry amendments are good to use in coir. However if you are feeding with a liquid style feed and getting systematic runoff its kind of a wasted effort as amendments need time to break down and getting runoff tends to flush out all their available nutrients. If you are already using amendments then start slow.Guano can be strong for plants and wear a mask. Mix it into the top layer.

hey 👋 Honestly, it’s a bad idea in a coco substrate. Even if you add it as an amendment, its availability will peak at a moment you didn’t choose; as a result, you risk nutrient burn at that point, and deficiencies while waiting for it to become available ; not to mention its unknown effect on your pH. Coco is neutral but sensitive; it needs a well-established routine

You will still need to use a coco base fertiliser or similar

Mix some into your coco and have a patch at the top which has no guano in so you don't burn the seedling and when the roots actually get to the guano she will use that for roots n shoots..

if you are treating the coco like a soil, sure, why not. If you are treating it as a soilless medium, then no, you should not. coco has no nutrients, so you need to provide a full diet one way or another... there's more than one way to skin that cat. Sounds like you want to run a soil grow, so you should buy a soil or make a soil etc. that can include coco coir, of course, but it needs more than that. in a soilless/hydro context, a 70/30 coco+perlite medium is fine. I''d recommend Promix hp or bx with 50% vermiculite as an alternative that is likely better. Soilless hydro is a no-brainer. you provide a steady complete diet each irrigation with 10% runoff waste out the bottom, which prevents buildup in the medium. Easy-peasy. No adding shit to the medium, no playing mad scientiest adding this or that here or there... Mixing these methods comes with zero synergy and likely negatives. I can't help with making a soil from scratch, but there are probably a shit-ton of guides out there for that. I'd probably only suggest that you use a 50:50 mix of perlite or vermiculite for a high-water capacity medium for propery aeration and drainage properties. If it's just coco, it holds less water and that;s why it's ~33% in that context. Again, 30% or 33% is not something to get nitpicky about. Recipes that suggest less of this type of amendment per volume are less ideal for roots - not debatable, just a fact.