'Best'....? You'll get lots of differant answers to that. The better foods will cost more...may require extra cost for shipping, if not local to you.
I think for tlapia...the 'best' is a balanced diet of a good fish feed, along with a variety of plants. Including duckweed, lettuces, spinach, sweet potatoe leaves, purslane (high in omega 3), ect.
I use purina's 'aquamax' products.
I buy the 400 for the little guys...I grind it for the tiny frys and as they get bigger, feed it whole, till they are big enough for the 3000 or 4000.
I ask my local purina dealer in advance, to have a bag brought in on his 'next order'...at no extra cost.
"Freedom is never more than one generation away from extinction. We didn't pass it to our children in the bloodstream. It must be fought for, protected, and handed on for them to do the same." - President Ronald Reagan
the Purina Aquamax we have here in the Philippines has added Calcium to help promote algae growth when I tried it it drove my pH to 8.2 and I had a very difficult time getting it back down as long as I used it.
I am using medium size pellets from the pet store a little more expensive but it doesn't drive the pH through the roof. But the guys from Purina told me they are working on a Aquaponic Feed that wont do that. They may have by now seeing that was a over a year ago now.