So when you say pesticides, are you referring to even organic where they're could be certain things that can be considered a "pesticide"
Yes. Pesticides are still used in organic produce, they're simply "organic" pesticides and in some cases more has to be used to be effective. Whether conventional or organically grown, most vegetables have to be treated to keep insects from eating them. I'm likely overly paranoid about these matters but anything that can kill a weevil or cabbage moth can kill shrimp in much smaller quantities. I'm not even sure I've had it happen, but I'm trying to eliminate every variable and now that winter is coming there's nothing left from my own garden to feed them. It's really tough to connect the dots in this hobby most of the time. I'm sure I could go back to blanching veggies and odds are great my shrimp would never miss a beat, but something went wrong with OEBTs, and my super tigers haven't done as well as last time I had a group.
I'm so hesitant to put my hands in tanks like I used to do all the time because I use hand sanitizer every time I touch money or a credit card all day at work. I'm currently putting medicine in my dog's ear. I changed the ink roll out on a price gun today and thought about what might be in that ink on my finger. So yeah, I'm almost certainly being overly cautious. But I've heard of a scented candle killing a parrot. I'm willing to go to some extremes if I can avoid screwing something up from my own carelessness. I'd never suggest that blanching veggies and feeding them to shrimp is dangerous. I just have foods on hand I trust to be safe and plan on using those from here on out unless I grew it myself. And it's not as if I'm feeding an elephant. At the rate I go through food even with 11 shrimp tanks, it's really pennies a feeding.
They're tank bred in the US but not in similar parameters, apparently. I have another tank I can set up, but I was told that the organic potting mix I used was increasing my KH/GH/TDS too much, and now the stratum is making it too low. I have a bunch of amazon swords and micro swords so I need some sort of plant substrate in there. Would it be okay to leave as is and just be very careful to acclimate the new ones, or should I come up with some sort of new tank setup with tap (around 4 kh and 8 gh, 200 tds) and plants in pots? Or organic soil with a stratum cap?
If I can keep the the tank as-is and they wont die molting, that would be ideal. I just don't know the best way to go forward to give them the best shot.
I don't believe that KH is a factor at all in failed molts. Perhaps GH can be but it's too big of water changes most of the time. If you look into my tank journals, you'll see that I have two high tech tanks in which shrimp were getting the white ring of death pretty frequently, when I thought this issue was behind me. It's not (well, it could
be a factor but not only that) lack of calcium or magnesium or phosphorus, or too much protein. In my view it's parameter changes -particularly after the shell has hardened post-molt. I went from 40ish % water changes every week to a 15% and though I have to use fewer ferts now, haven't spotted a one with it since. Same in my 125 gallon cull tanks. They have fish and for a decade I used to do 50% water changes monthly and particularly large females used to die from the white ring of death all the time. It's not my favorite thing to do, but for the last year or two I've done small weekly ones now and molting issues went away at the same time. I'm not an expert, I'm not 100% positive what I'm seeing is a result of this, but I am positive that this used to plague me and since changing gears never has since. When giving advice I tend to say that YMMV, but with this -if you have a stable tank I'd wager real American dollars that your mileage will not vary.