My tank has recently matured and Im starting to add fish. Slowly of course. I bought two fish last week (flame angelfish and Basslet.) This coming week I plan to add a clownfish. I was told by the local fish store guy that I should do a water change right after introducing a new fish. I was thought it was right after??? I do a 10% water change every week. I have a 110 gal, wet dry, Octopus Skimmer 110, (2) Rio 800 power heads, UV sterilizer, 35 lbs.ish of live rock. So when I add my clown fish, should I do the water change right before, or a little after??