Pearls are smaller than Silvers but waaaay more aggressive, i found them to be slower growing in general than the silvers and my Pearl grew from 1.5" with eggsac to 12" in a year and a half in a proper sized tank, he was quarantined in 240L moved and grow on in 340L and moved to a 1500L very quickly... (8x3x2 with huge sump).
Silvers i have seen grow at a scarey rate... allowing thm to feed from the bottom of the tank leaves them searching downwards for food too often, you'll end up with an Aro with dropye.
I had to agree with Gasmask on this one, its shameful someone would make such a superb fish suffer through lack of care and pure selfishness of 'well... i want it!' attitude....
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That aside, i found getting the Aros as real babies was the best way, they are bloomin fast growing and getting them small means you can pretty much get them to eat what you want...
When they are so young, a floating cube of bloodworm is easy to swap to a block of krill.... mysis.. tubifex... a floating prawn... a bit of chopped fish... a pellet....
Get the timing right for the change in foods each time (not so long they get hooked... but not so fast the fish doesnt get to like the food).
Dry food wise, I found the JBL NovoDragon to be really good and supplemented it with algae/lower protein floating cichlid sticks. From what i read, wild Aros do sometimes scavange tree roots/tuber things and green stuff to supplement their diet and i found adding greenery did amazing things for the Pearl Arros colours! He loved peas!
I did feed a lot of Hikari Massivore Delite (i swear by these pellets for stingrays too!) but i only fed them when my arro was an aggressive enough feeder that he would grab each pellet as soon as it hit the water.
I think peoples BIGGEST mistake with Arros in terms of feeding is offering them live shrimp/feeders. Its a one way road really...