I have play sand in three tanks. 80 gal.75 gal, and 29 gal. I used about one pound of sand per gal. Rinsed it all in a large rubbermaid tub several times to get all the dirt and loose particles out. I then placed the sand in the tank using a small plastic dustpan. I then placed a plate on top of the sand and filled the tank letting the water hit the plate. This helped tank from clouding too bad. The larger the container you use to rinse the sand, the easier it is. When it is rinsed good ,, You can pick up a handful and let it fall to the bottom of the tub you are using for rinsing it in, and there will be little clouding and it should all fall to the bottom. If suspended particles are present and do not settle immediately.. Rinse it again. This will help keep fish or tank maint from kicking up small or loose particles that could find their way to the filters internal parts. I would leave the filter or filters off for at least three hours after placing the sand in the tank and filling it with water. In this way any loose particles will have settled to the bottom of the tank. Try not to place the filter uptakes too close to the bottom of the tank. This way there is less chance of the sand winding up in your filters internal parts. Always vaccum the sand BEFORE you sift it or stir it. That way you can remove the loose stuff on the top rather than burying it in the sand. Hope some of this helps.