new to rays... but I keep my 2 retics in 450ish tds, ph sits at 7.8 -8.0 and my gh/kh are both off the charts.... I also keep an aba aba knife, clown knife, clown loaches, and spiney eels in this water... and everyone is thriving. I concur with stability stability stability.... the water in the house goes threw a softener... but I usually fill from an outdoor facet that isn't hooked inot the softener. Well water is great for the planted tank though... the biggest problem i've had is with algae, mineral rich water, and any amount of nitrates and light and it goes crazy... pothos been helping alot.. many of my tanks read 10ppm or less nitrates regularly ( still do regular weekly water changes)
And anytime new fish are added.. I drip acclimate best as possible, and match TDS levels. been awhile since I've lost fish.. and then that was some clown loaches.. took me awhile ( had to buy my TDS meter to figure out why i kept loseing them) and had to do some massive water changes on a "perfect" tank...not sure how it happened but my tds where over the max setting on the meter.