Keys for Reactor water

I have created a wave effect with reactor water (by dropping an object in

it) and created the rest of the animation according to the necessary timing.
For some reason, I need to insert some more animation before the wave effect

starts, so now I need to move all animation forward about 300 frames but

there are no keys for the reactor water object.
There's no range identifier in Dope Sheet either.

I wonder if there is away to change the start frame of reactor water object.