to be fair the nitrites were zero by 6pm. So day and a half. I dosed again at 6pm yesterday and the nitrites were 0.25 at 8.30 this morning. I suspect they would have been clear by 6pm.
I won't know though because the filter has been put on the new tank. I dosed again in the new tank, so will see what its like in the morning.
The other black sponge, fine pads and bio wasn't cleaned, only the big foams. Im pretty sure it'll be fine