Update:
Here is the system I am using for auto-topoff:
The tee is connected to the return line for my eheim and the metering pump injects fresh water from a 8 liter resivior directly into the line (so there is still no visible equipment in my tank). I have the dosing rate set so that it adds 0.75ml, eighteen times every hour, 24/7 - which is my evaporation rate.
I am pretty pleased with the results
. I never would have thought that my nano would end up being my most stable tank in terms of salinity.
- Chad