Out with the gravel in with the PFS. I think it looks great and the fish seem to love it. Process took about 5 hours yesterday but well worth it.Just got back from lfs they tested the water and so far it's perfect. Will have it retested in 2 days.. When takeing out the old gravel i Left all fish in tank and used kitty litter scooper to remove old gravel thinking it would leave most of the good bacteria in tank. Added the sand did a 30-40 percent water change and so far so good. Thanks for all the tips on how to do this.