Like most things aquarium related, I cannot find consistent advice about TDS and the more I read the more confusing it gets. I get that TDS is pretty much a measurement of everything 'extra' that's in the water. After watching Cory's video about TDS my understanding is that it's most useful as a quick check to see if something is 'off' in the tank and unless it's fluctuating a lot, the value isn't really all that important. But I have some crystal reds coming next week and I know they're more sensitive than most shrimp. I keep seeing that their preferred TDS is around 140-160. All the values I've been measuring in their tank is consistently right in their preferred range except for TDS. Out the tap my TDS is already almost 180 and in my tanks with fertilizers and everything else I've seen it measuring between 350 and 450. I did test my meter with distilled water and got 2 ppm so the calibration doesn't seem to be that far off.
What I've seen recommended is using RO or distilled water for CRS and adding gh+ until the TDS is in the right range. That's making me think that it's only the water components that affect GH that are important in the TDS reading for the shrimp. And my tap water has no GH. So does that mean I shouldn't worry about the TDS at all if my GH is now in the right range (I'm adding Bee Shrimp Mineral GH+)? Or am I wrong about that and it would be safer to just use distilled water instead and add gh+ to it? I'm probably way overthinking this. I never checked TDS until now and everyone in my other tanks has done well.
If it helps, here's my normal water parameters:
Tap water: ~5 nitrate, 0 nitrite/gh/chlorine, ~40 ppm kh, 8.2-8.4 ph, 178 TDS
In tank (heavily planted, use extra Easy Green fert, lots of wood, gh+, etc): ~5 nitrate (didn't add more fert yet), 0 nitrite, 100 ppm gh, 0 chlorine, 0 kh, ~6.8-7 ph, 372 TDS