Thanks so much!!
And thanks for the specific links, Mark - I was checking around your site because on one of your videos you mentioned a refractometer, but then I couldn't find it again --
Also, I'd look into the Hydro Logic, but I'm just renting the current place (after it took me a year to sell the money pit, I mean my house, I decided against buying for awhile). Assuming those larger systems would have to stay with the place...?
Best,
-eLizzy