Now that the tank has been filled a few days, sump running, and a few fish and lots of plants added, (but being anal about these things).
I realize I'm jumping the gun a bit, but starting to test the tank water, and will keep a log to detect changes and trends as the fish in cycle begins, and things progress.
My "tap" water has a pH of 7.6
The tank, slightly higher at between 8 and 8.2.
I believe this is because some of the substrate is coral sand from off the Pacific beach 50 yards across the street.
Ammonia and nitrate both zero.
With the 25 x 1" or less Gambusia as the only fish in 180 gallons, this is no surprise.
