Instruct: Classify the given Amazon review as either positive or negative.
Query: Terrible toy

This tank kills fish. We have lost four fish in less than a week. At first we thought we had done something wrong, but after reading the instructions several times, testing the water, and talking to the pet store, we have determined that it is the tank. We knew something was up when our two fish died at almost the same time (just a couple hours apart). We replaced the fish and the same thing happened. We will not be sentencing any more fish to death in this dud of a tank.