I brought home 5 honey gouramis and a teeny weeny baby BN (maybe 3/4 inch long, if that) on friday to add to my new 30 gallon tank that was currently holding 5 guppies. It's a brand new set up but I had been running the filter on another tank for a week. The little pleco seemed to be doing really well! He was wiggling all about and munching on the logs and the algae-covered rock I moved in from my other tank for him. But this evening, I found him no longer alive I am a little bit heartbroken. I'm thinking he was just too tiny and the move was too much stress for his little system. I tested my water after I found him and I have a very slight ammonia reading, not even 0.25ppm, and I did a 50% WC. Ni/Na are 0/10. As of yesterday afternoon, water was 0/0/10 so I think the ammonia came from the dead fish. All the other fish are doing well with no signs of issues. I just want to know if there's anything I could have done differently or should know for next time, except for get a slightly larger baby pleco!