live rock and sand turning a grey color

i took a sample of my water to the LFS and every thing was fine there but my live rock has little white things everywhere. its making every bit of my live rock look like there is snow on it and my sand looks like it is turning grey.fish are healthy i only have 2 crabs so far going to order more.LFS charging 4.99 for crabs and 5.99 for snails.any help would be great.my new camera sucks so no pics sorry

 

how long has your tank been set up? Is it growing on your rock or just sitting there like dust? If it is like dust, the only thing I could think of is that you are experiencing some carbonate/calcium precipitate. The reason this would occur is if your calcium is too high

 

yup just sitting there like dust.my tank has been up for about 6 months.walmart was out of distilled water so i went to the LFS,wich bye they way Sucks!!!.I decided to buy 10 gallons of there water and that was when i had mine tested.i never had this problem until i got there water. i will never do that again,and the lady is a jerk to boot.one minute she will sell you soemthing and the next minute she will say your not ready.just blowing some steam.How can i lower this

 

The only thing i can suggest is to try to do some water changes, without using the lfs water and try to suck as much out as possible, then see what happens

 

pretty sure the white stuff is just sponge, you can clean it off if you want or the fish if you have any will eat it,

i know this because i went to the lfs and asked them cause i have the same thing on one of my rocks.... its no problem apparently

 

no its no sponge it is like grey dustdoing a water change tommorow see what happens also how do you lower PH