Water change effect on RCS and Amanos?
I did a large water change the other day, ~60% and noticed both RCS and Amanos went into hiding afterwards. I don't see any dead ones, ammonia spike, or empty shells. I still see some hanging around and eating and they seem to be increasingly back in view now two days later. I'm making other changes in the tank, such as recently added a few more of each shrimp and still dialing in CO2 and light. So their behavior may not be related to the water but I want to get some water change "best practice" from people who raise them in a mixed tank and understand what TDS changes are critical or concerning.
Generally, in addition to a weekly ~50% change, I do 2-3 small (5-7%) informal changes during the week as I trim and clean. I'm using water straight out of the tap, 2x Primed in a bucket first. It's not really an option for me to let water sit out for days or I'd probably do that.
Reading about RCS sensitivity (and assuming Amanos are similar), it sounds like a 50% change might be too much for them, particularly with a large TDS shift.
At the last water change (~60%), when they went into hiding, my parameters changed from:
TDS ~ 340
TDS ~ 260
Is that enough of a change in parameters to cause a problem or behavioral change with shrimp?
Other tank stats:
50 gallon, CO2 injected to ~ 20ppm during lights on
Heavily planted > 90% and dense
~ 40 endlers (many of which are fry or juvvies)
~ 100 RCS (if most purchased are still alive, gradually added over last 2 months)
~ 14 Amanos (if most purchased are still alive)
I am thinking I should maybe break the water changes into 3-4 20% changes per week to be more gentle on them.