Wow I killed my poor fish (Help)

[tfast500]

I have had my tank setup now for several months and my tetras were happy however I decided to add in two new fish to the aquarium they were like mini plecos not sure what their exact name is but they are grey in color compared to the black common pleco, anyways I let them get use to the tank and they were doing great. recently i decided to change the substrate from green gravel to crushed coral which now I am thinking was a horrible idea. my fish started acting funny a week or so with the new sand. i noticed white dots all over all of my fish so i bought some ich attack kordon brand natural chemical i put it in last night however i woke up this morning to find 4/6 tetras dead and 1/2 sucker fish dead


Im very upset and i don't know if it was the chemical, the ich or the new crushed coral

I put my fish through hell and I feel really bad.

I went to the store to buy the API master kit and did a test

results:

PH: off the chart (high)
Ammonia 0.25
Nitrite2 0
Nitrate3 0

 

[ram_g0p]

You've got the answer yourself. The crushed coral had sent the pH way up high! Usually, (crushed) coral i added in small amounts to adjust the pH as desired. Never as a substrate in large amounts!! I am very sorry this happened