Ya, do a water change. Your param's are good, but doing a water change replaces the trace elements in the water, things that you don't generally test for, but are good for everything in your tank.
I got four Naser snails and ten small blue leg hermits
. The snails started to burrow right away and the hermits went to work on the rock.. my emerald crab looked a little annoyed there were all these little guys eating his food.. he ran all over the place eating where they were eating lol.. here are pics Oh and in that middle picture you can see a burrowed snails anntenna.. its neat: