Although Tin foils are omnivores they tend to get more and more vegetarian as they age, they have been observed in nature eating terrestrial leaves, aquatic and semi aquatic plants, and filamentous algae.
My thought is that food made for Tropical fish may be too high in protein and misc. animal products.
A high quality vitamin enriched pellet made for goldfish and koi might be a better choice.
The barbs and koi are very close relatives.
You may also be pushing the envelope with those large fish in a 90, and because of their size and inevitable waste output, you water change schedule may need to be upped to keep up, in that size tank.
I'd test for nitrate to see where you may need to go.
If your nitrate is 20ppm by mid week, doubling water changes to twice per week might be advised if and when it hits that concentration.
If nitrate creeps up to 40ppm tripling or quadrupling to keep up may be a good idea.
My thought is that food made for Tropical fish may be too high in protein and misc. animal products.
A high quality vitamin enriched pellet made for goldfish and koi might be a better choice.
The barbs and koi are very close relatives.
You may also be pushing the envelope with those large fish in a 90, and because of their size and inevitable waste output, you water change schedule may need to be upped to keep up, in that size tank.
I'd test for nitrate to see where you may need to go.
If your nitrate is 20ppm by mid week, doubling water changes to twice per week might be advised if and when it hits that concentration.
If nitrate creeps up to 40ppm tripling or quadrupling to keep up may be a good idea.
