Why my fish died

In this lab, we are trying to find out what is the cause that make fishes died.

We make 8 samples, bromothymol blue is added in 4 of them. The temperature was measured in the table below

Sample	Temperature (celcius)
1	29
2	28.5
3	28
4	29
5	28
6	28.5
7	27.5
8	27

1.       Why do they die?  What's your hypothesis?

Answer: because the temperature was too high and the plant can't get enough sunlight

2.       What are our variables?

Answer: temperature, pH, O2

3.       Which container increased in temperature the most?

Answer: 

4.       What were the initial temperatures?  Are there any increases