With my new and calibrated TDS meter my caridina aquarium is at 218 ppm! Still higher than I want, but far better than my original readings with the other meter. I'm going to add the purigen and see if that brings it down. Fingers crossed that I'll have everything right soon!
Yes - one recommedation: wait!
Adding a small amount of KH / buffering will temporarily raise the pH, until the soil absorbs it and the pH goes back down again. You can keep going like that until the buffering is exhausted, but then you have no buffering capacity left which kind of ruins the soil. With time the pH will naturally start to rise and should stablise at the levels you want. But adding KH will just cause the pH to fluctuate which is probably worse for the critters than a stable but slightly low pH would be. So my advice is to do nothing (except don't add too much drift wood, leaves, etc that might reduce the pH further).
I thoroughly recommend this model:
Works great, digital calibration with the buttons on the front (no faffing round with a small screwdriver), reliable, good quality. Cheaper TDS meters do not have temp compensation so, if you're bothered about accuracy (and I'm not sure how much this affects readings across typical aquarium temps), get one with temperature reading and compensation.
I didn't know that about pH! Thank you, I'm glad it's not something to be too concerned about right now. I figured it'd stay roughly where it was and I'd always have < 6.0 if I didn't find a way to bump it. I'm still new to remineralizing water, my tap parameters are suitable for neos but I don't really trust it not to have something toxic in it that'd murder my little guys, so I invested in a RODI when I decided to get shrimp.
That's the tds meter I ordered actually, it was "frequently bought" with the calibration fluid you linked. Glad to hear a firsthand opinion of it! It should be here tomorrow and I'm really excited for it haha.
I have the blue model TDS meter.... but I just might have to grab that fancy smancy one!
I got into shrimp keeping because of someone else! As in... I had to buy stuff to figure out why THEIR shrimp were dying. I have now stupidly overstocked my tank with fish.... not that it's an issue atm... I need a bigger tank! lol
Oh no, a bigger tank? That sounds horrible...
I tried keeping shrimp once several years ago, had some low grade cherries from a LFS, they lived and did pretty well but never bred. One or two of the females were berried when I got them and the eggs hatched and the fry grew up without issue. Females were saddled but never berried. I didn't really know about parameters and tds then, so that was probably part of it.