That's what I'm heading forThe one thing I can tell you for sure, the first time you spot new eggs or fry you will find yourself doing the happy-fish dance. Trust me, I know. I have been doing it for about 19 years. I still do it.
When I didn't have that much sand like I do have now, my amazon sword was literally running on detritus and it got quite bushy with healthy and happy leaves to my surprise.My sand has many, many plants so I can't do more than a very light "swirl & vac" at most. Detritus breaks down & sifts into the sand. I have pool filter sand, a fairly large sand that is sized to collect fine debris...& it does, lol. But I don't have very many fish so they don't poop enough to keep heavy root feeders like swords happy. It's easy to tell when the root tabs run out, there are more than a couple dying leaves.
The only time I see cory eggs is if they lay them on the glass & I notice before they get eaten.
Like TTA said, the behavior is fun to watch even if you don't get fry. Another hint, fertilized eggs are tan (ish) soon after, white means infertile.
Good luck!
I knew about the eggs I watched couple of videos on YouTube how coried mates, it is fun and kinda cute lol.