Mystery Deaths

Neo Shrimp tank only Planted

Been up and running about a year. A month ago I switched out to a canister filter and changed my substrate from gravel to sand. I put all my filter media into the new filter. My levels have stayed at zero. So parameters have been consistent and WNL.

I usually find a larger shrimp dead once a month or so. I have 80+ in a 5g tank.

Randomly last night I come home from work and saw a younger juvenile dead and upon inspection noticed another 6 or so all mostly juveniles about 0.25" and one of my adults.

I have never found more than one dead at a time.

I added some new plants which I dipped in peroxide and rinsed very well on Tuesday. Would it have taken 72 hours for a pesticide to have killed them or I would of seen more immediate effects? Any other ideas what it could of been??

Thanks for your time!

Neo Shrimp tank only Planted

Been up and running about a year. A month ago I switched out to a canister filter and changed my substrate from gravel to sand. I put all my filter media into the new filter. My levels have stayed at zero. So parameters have been consistent and WNL.

I usually find a larger shrimp dead once a month or so. I have 80+ in a 5g tank.

Randomly last night I come home from work and saw a younger juvenile dead and upon inspection noticed another 6 or so all mostly juveniles about 0.25" and one of my adults.

I have never found more than one dead at a time.

I added some new plants which I dipped in peroxide and rinsed very well on Tuesday. Would it have taken 72 hours for a pesticide to have killed them or I would of seen more immediate effects? Any other ideas what it could of been??

Thanks for your time!