HCA: Hermit Crab Association

Case ya'll don't remember I work at a bait store so we sell minnows, worms, and a few other baits.Yesterday I change out part of the water cuz I notice we're losing a few more than normal. Checked the chlorine level and ph level they were fine so I went home and today I get back and we start losing a ton of minnows (figuratively speaking) we just ordered some more for this weekend and the guy that worked before I did didn't say anything about us losing minnows. I call and start griping out our minnow guy and he said we were losing a bunch before/when he got here and no one else has had a problem with the minnows he brought. So now I have to get all the dead minnows out while trying not to get the live ones which is a lot easier said then done. I cleaned the tank over again and lets hope that fixes the problem or we're going to be out a lot of money. My big belly didn't help either. Still don't know what happened to them.

If there is anyway to set up another tank for another shipment of minnows so that you can keep the new from the old and then this way you can tell if it's his fresh shipped one's that are dying off and killing off your others or if you have a issue in your tank.