Brutal Sunday

[tidal_waters]

Great forum here and was hoping to get some help, as I'm still pretty new to the hobby.

I was out camping for the weekend and came home to my tank missing a clown, presumably dead and eaten by crabs, and the second blow was I was picking out what I now know is zoa eating nudibranch,s. I pulled about 8 out so far off the polyps.

So now the two questions. With the death of the clown I noticed my nitrates spiked and I changed about 20 percent of my water. Is this going to be enough, or should I whip up another water change tonight.

Now onto the nudis, I know I have a problem on my hands from what I read but I was hoping to get some information or past experiences from some of you that may have had this problem in the past and what steps I should take next to get rid of these guys.

Thanks in advance!!