Take extra caution when moving rocks around in an establish aquarium containing fish. The minute hobbyists put their hands into the tank, the fish will hide behind, in between, and underneath rocks. When we move these rocks, the fish can get trapped in between two pieces and get crushed. Additionally, if the rock is removed from the tank, any fish hiding in the crevices will be exposed to air. So either keep the rocks in a bucket of water, or don’t let them stay out of the water for more than a couple of minutes. Don’t rush things though, but take your time and get the rocks situated the way you want them, otherwise you’ll just have to do it over again when the inevitable cloudiness disappears.