Kalk paste pellet harmful to fish?

[Zhugelaocunfu]

This afternoon I just applied some kalk paste to kill a aiptasia found in my tank,after a while I activated my wave pump and didn't expect it being blown away(although the aiptasia grow on a flow demanding coral fragment,I didn't expect the flow to be that strong),and when I go out for two hours and came back, my dart fish (the only fish in my tank) is ded, it still eats food like usual at noon when I feed it...

 

[Tanglover1]

This afternoon I just applied some kalk paste to kill a aiptasia found in my tank,after a while I activated my wave pump and didn't expect it being blown away(although the aiptasia grow on a flow demanding coral fragment,I didn't expect the flow to be that strong),and when I go out for two hours and came back, my dart fish (the only fish in my tank) is ded, it still eats food like usual at noon when I feed it...

It raises pH and mess with alkalinity and water chemistry. Still see what other's say. Fish usually spit out kalk paste so problem is regarding water chemistry. U may also hv put it in high quantity