I would point out that the new laws on ballast water. Are to dump the fresh out in the ocean. In favor of bringing massive saltwater dumps into the lakes 
In all honesty I don't spend any time at all worrying about it. With the ease at which some of the items in my tank die off. With something as simple a 2 or 3 degree temperature change or insignificant pH change. The entire tank will go belly up.
So dumping any of it into my 60 degree toilet water, with a 2 or 3 point pH change. And then chasing it will 5 gallons of 120-130 degree water from ye old bathtub, or peroxide, or bleach, or all of the above.
I sleep just fine at night.
In all honesty I don't spend any time at all worrying about it. With the ease at which some of the items in my tank die off. With something as simple a 2 or 3 degree temperature change or insignificant pH change. The entire tank will go belly up.
So dumping any of it into my 60 degree toilet water, with a 2 or 3 point pH change. And then chasing it will 5 gallons of 120-130 degree water from ye old bathtub, or peroxide, or bleach, or all of the above.
I sleep just fine at night.