I know, it sounds crazy, but some brands of fish food contain copper. It's usually in the form of copper sulfate, and it can wipe out your inverts at the gut level!
I was feeding my fish, shrimp, and snails Wardley sinking shrimp pellets and flakes (Sorry to call you out by name, Wardley) and I noticed I was having a hard time with the population thinning... it wasn't obvious at first. When I noticed the inverts dying (fry first) I started testing water quality very frequently. Hundreds of baby assassin snails were everywhere, then they were less and less visible. Shrimp fry started disappearing. Shrimp never bred (RCS). However, water quality was perfect. I was baffled until someone here said something about testing for copper, and then it hit me that the only way copper could be getting in the tank was by something I was putting in. Ingredient check!
I tossed the food, and put in a Seachem CupriSorb sachet to soak up any resident copper left in the water. Now I check the ingredient list EVERY TIME I buy food. You never know when a company is going to change their formula even. Everything is back to normal for me now, and I hope that my posting this helps others.
I was feeding my fish, shrimp, and snails Wardley sinking shrimp pellets and flakes (Sorry to call you out by name, Wardley) and I noticed I was having a hard time with the population thinning... it wasn't obvious at first. When I noticed the inverts dying (fry first) I started testing water quality very frequently. Hundreds of baby assassin snails were everywhere, then they were less and less visible. Shrimp fry started disappearing. Shrimp never bred (RCS). However, water quality was perfect. I was baffled until someone here said something about testing for copper, and then it hit me that the only way copper could be getting in the tank was by something I was putting in. Ingredient check!
I tossed the food, and put in a Seachem CupriSorb sachet to soak up any resident copper left in the water. Now I check the ingredient list EVERY TIME I buy food. You never know when a company is going to change their formula even. Everything is back to normal for me now, and I hope that my posting this helps others.