Wow, just learned something about my 75g tank this evening! Have not honestly tested Nitrate levels for MANY months - the API kit always showed 40-80ppm and just assumed that was normal for my tank (or the API kit). So on a whim I tested the Nitrate level this evening (tomorrow is water change day). I actually got a big fat "0" on the test. Basically shocked, I tested the wifes high tech 40g barb tank (assuming the API kit was just dead). Well, that tank showed a nice 40ish ppm so I guess the kit still works. Looks like I will need to up my KNO3 dosing from 1/2 tsp to 3/4 tsp (3) times per week and test again.
While I had all the test kits out figured I would test a few more things. Realized after digging thru everything I have an API Ca2+ test kit also.
Ca2+ = 80ppm
GH = 15 at the tap (API test)
GH = 17 in the tank (API test)
KH = 10 at the tap (API test)
KH = 9 in the tank (API test)
Ammonia = 0
Nitrite = 0
Did not test Magnesium level this evening, but it was around 12-16ppm before I dosed the Equilibrium.
So, given the rather high 17dGH (approximately 304.3ppm) and only 80ppm Ca2 I wonder what else contributes to the high 17dGH?
Anyway, looks like I have some more learning to do

For now the best I can do is show off what I learned on my LG-G6 phone - manual video settings!!! This just might be the clearest video I have ever done on this tank. Make sure you use the 720p / 60fps setting if you watch it.