perhaps you misunderstood what I wrote. “Cannot be optimal for all aquaria” only means that there is at least one aquarium for which it is not optimal, and that is guaranteed to be true.
I think you may have interpreted it to read as “cannot be optimal for any aquaria”, which I am not claiming based on my rationale for the statement.
Yes, I keyed in all. But then wouldn't that also be true with other products mentioned?


