Judge Holden;4732952; said:Neither do some posters on MFK.
The phenomenology of fish is terra incognita. Do you know what it's like to be a fish? How was this knowledge acquired? Surely they have conscious states, the precise nature of which is open to debate.
They have preferences: my Oscar "prefers" pellets to gravel
You must have some serious ammonia readings if your Oscar has Hikari's as a substrate.