Honestly not a major issue to get salinity spot on anyway for me its so easy to just get such a small amount of water 2gal right by just going by the 1/2 cup rule for myself (tho still double checking salinity with the trusty refractometer) & assuring im always topping off evap ea. day, it never sways. I can understand on systems of larger amounts & yea i know salinity varies greatly in the wild. Id be lazy tho to let my nano prams vary wildly since the effects are greater in small systems. I only test everything else 1 time a month and nothing has ever varied using Reef salt mix. I prefer stability on all the elements all the time part of the fun of keeping water spot on. However if you saw my work truck you would say yep, he surly is not anal retentive tho. LOL.