Instruct: Classify Amazon reviews into positive or negative sentiment
Query: 5 dead fish later.... don't even bother

I bought this toy for my shark-crazed 5 year-old... she was so stoked and we prepped the tank, added the recommended water chemicals and dropped in two small goldfish. Less than 24 hours later, they were dead. Repeat... 40 hours later... same story. We tried a single Betta, Frank, but less than 4 days later... he's dead. We don't know what it is. The water was tested, it's fine. We think it is the overall design of the tank, could the tight-fitting lid be responsible? Possibly ammonia by-product buildup from the fish? Who knows. But we have given up and are dumping this promising toy into the trash bin.