Ok, I've had my tank for a while, so I know most of the ropes. But today I switched to sand (specifically for fresh water [won't spike my PH]). I know it's normal for the water to be cloudy, but when should I add my fishies back in? (It's a sorority). The cloudiness has gone down a lot since I put in the sand, and it looks nearly clear. But I just want to be sure. Any ideas?