There have been many threads / posts addressing the problem of cloudiness when filling a tank with water when various substrates are used. The degree of cleaning and rinsing is often raised as a cure for cloudiness and that is certainly important; however, the way in which you add the water is just as important. Always put a shallow bowl on the substrate surface and gently pour the water into it letting the water over flow the bowl. This reduces turbulence and decreases currents that will kick up fine particles. As an example, this past weekend I set up an experimental plant nursery tank with soil and play sand. I saturated the soil and squeezed out the water and placed it evenly in the tank. I cleaned the sand well and placed that over the soil evenly. Next I put in the plants by poking a hole in the substrate, putting in the roots and covering them up with the sand. Then I used the bowl technique to fill the tank with water. The tank was clear immediately and still is. Just my thoughts and experience on this issue that I hope will help.