Found hitchhiker coral during cycling

[antimatter]

My tank has been cycling for about a week now. I got the rock and some water from an established aquarium. I found some corals (shrooms and I think some kind of leather coral). They seem to be doing fine. Might even be growing a little.

My question is if I should be doing water changes/soft cycle now that I found these corals.

My tank already went through an ammonia spike.
my ammonia and nitrites are zero, but my nitrates are high(20-40)

thanks for any advice

[Reefscape]

If your tank is still cycling, then, water change at the end of the cycle..Do a nice large 50% change..