Thank you for all that. The specific question I had was more about which species to start with in the tank? I had assumed corys, since they will be on the bottom, but a school of black skirt tetras or neons would probably be less expensive. It may not matter. That is why I ask.Flyfisha said:I don’t wish to be rude. But tetras is a name given to multiply fish that have a special fin on their back. I believe piranhas are a tetra?
Most tetras in the hobby are not aggressive to other species. Many are aggressive to each other in small schools . That is why 6 or 8 are considered an absolute minimum. Perhaps this is a consideration in you intend to stock . 5 fish wait and add 5 more then add 10 a fortnight later?Then 20 more. Etc. Doubling the stocking each time.
Adding a small group of corydoras followed by another small group is going the avoid the aggression problems of a small group of tetras.
The tank is cycled by now TeachEng18 ?
Congo tetras are one of the aggressive species that’s common in the hobby.
Corydoras often experience barbel erosion with immature substrate, I believe.Flyfisha said:The tetras first will work . I would still add at least 6 at once. Just watch the ammonia in the tank. I don’t trust fishless cycles to hold up to real world bio- loads. Of real world ammonia. Just my crazy opinion.
As far as bio-loads just don’t feed so much as to have uneaten food sitting on the substrate.
All this sounds a bit obvious , but many of us still feed to much per day into our tanks.
Both tetra species mentioned will eat from the substrate as will corydoras so that makes no difference.
I have no advice on what species needs a more mature tank substrate? Corydoras don’t eat algae, not much anyway.
You ask “which will have a greater bio- load.“
I don’t have a definite answer sorry.
I believe the body size to be similar in juvenile fish?
They don’t need food every day but are probably not getting feed a lot in a shop? And if being posted recently to the shop not feed beforehand.