If you can, create multiple quarantine tanks (3-4, if you're regularly adding new animals/plants). I still have a few left over from when I had my full scale breeding setup. I use cheap hard plastic tubs. I double stack them to create an insulated barrier, and keep ~15g of water. While not in actively in use, MTS help to keep the cycle.
You mentioned that you use 'spring water'. Is this from a well on your property? No matter the origin of your source water, check it for metals. Use R/O to replace the volume evaporated. Use mixture of 60% source water and 40% R/O when doing water changes. That's a general approximation. Calculate that ratio by how much water you change, and how frequently you do water changes.
The only other thing that comes to my mind is, I have a friend who once added a rock, she had found while hiking, to her tank. As an unintended side effect, the rock started leaching ammonia compounds. She was able to find the culprit and fix the problem, but she lost about 10% of her shrimp.
My rule of thumb is: Whenever adding anything to a tank, QT for a month prior to placement in it's permanent home. I QT everything, including leaf litter (and I soak my leafs for about a month before placing them in a QT. If I ever find that something is off, in a quarantine tank, I resolve the problem (if I can), and always empty the QT tank, throw away the sponge filter (I make them for about $3 each), scrub the tub with water, then scrub again with a very weak hydrogen peroxide solution, finally rinse with water and let dry. Then it's ready to be rebuilt.
I rebuild a QT tank by taking a redundant (pre-aged) sponge filter from a growout tank, take 20% of water from the same growout tank, and add a handful of MTS. I let the light go for 24x7 for a week or so, and add about a gallon a day, until I reach ~15g. After a few weeks I'll add a few guppies, if the water checks out.
I realize that these steps are a bit extreme, but from what I've read, you're doing things similar to what I did for the past 15 years. That is, breeding shrimp for sale. Because I was breeding so many, I was very cautious of shipping sick, or stressed animals. Early on, I encountered a few 'businesses' that sold shrimp that weren't fit for use as live bait.
Good luck!
You mentioned that you use 'spring water'. Is this from a well on your property? No matter the origin of your source water, check it for metals. Use R/O to replace the volume evaporated. Use mixture of 60% source water and 40% R/O when doing water changes. That's a general approximation. Calculate that ratio by how much water you change, and how frequently you do water changes.
The only other thing that comes to my mind is, I have a friend who once added a rock, she had found while hiking, to her tank. As an unintended side effect, the rock started leaching ammonia compounds. She was able to find the culprit and fix the problem, but she lost about 10% of her shrimp.
My rule of thumb is: Whenever adding anything to a tank, QT for a month prior to placement in it's permanent home. I QT everything, including leaf litter (and I soak my leafs for about a month before placing them in a QT. If I ever find that something is off, in a quarantine tank, I resolve the problem (if I can), and always empty the QT tank, throw away the sponge filter (I make them for about $3 each), scrub the tub with water, then scrub again with a very weak hydrogen peroxide solution, finally rinse with water and let dry. Then it's ready to be rebuilt.
I rebuild a QT tank by taking a redundant (pre-aged) sponge filter from a growout tank, take 20% of water from the same growout tank, and add a handful of MTS. I let the light go for 24x7 for a week or so, and add about a gallon a day, until I reach ~15g. After a few weeks I'll add a few guppies, if the water checks out.
I realize that these steps are a bit extreme, but from what I've read, you're doing things similar to what I did for the past 15 years. That is, breeding shrimp for sale. Because I was breeding so many, I was very cautious of shipping sick, or stressed animals. Early on, I encountered a few 'businesses' that sold shrimp that weren't fit for use as live bait.
Good luck!