need advice on litter box use by fusssy cats

I have been using a store brand (Aldis) litter in my two boxes. Someone gave my cats a gift card to a pet store so I used it to buy two large boxes of Fresh Step. I cleaned one of the boxes and refilled with Fresh Step. It has been a week now and only one of my three cats will use it. The other box is really running low on the old litter but I'm afraid to empty it and use the new litter because if they won't use the  one I used FS in then I'm sure they won't use this box, and then where will they go. I have never had this problem before and am puzzled. I have noticed that FS is very dusty and is scented.I always thought that Fresh Step was a premium litter.  Maybe that's the problem but in the meantime how do I get them to use the box with FS in it. Advice please

Here's a good article on kitty litter:  http://www.thecatsite.com/a/litter-box-maintenance    The best way to change litter is gradually, adding a little of the new to the old and increasing the amount over time.

My one experience with Fresh Step lasted less than 24 hours. The dust and the scent were so invasive I couldn't breathe when I was in the same room as the box. I can only imagine what it did to my kitty's lungs. I stay away from scented litters no matter what the brand. I've heard that Fresh Step makes an unscented litter, but don't know if that cuts down on the dust. I'm not willing to spend the money just to find out.

of all the reviews i've read here on this site and else where, as well as what i've heard from my friends who use FS, is that it is very Dusty, and HEAVILY scented. These could be factors why your cats don't want to use the litter box with FS in it. I know that cats do not enjoy using scented litter, but some will.

try to look at the properties of your old litter and try to buy something similar for your kitties to use, for example, is it scented? how is the texture? etc. If FS is not working for you, you should be able to return it, as it will be a waste if you can't even use it because kitties won't use it.

If i may ask, why did you want to switch the brand of litter your kitties were using? they seemed to like their litter just fine, is there a particular reason you thought they needed the change? did you just want to try a different brand??

if you check out the reviews section on this site, other litter, you will see a lot of review on litters from users of this site that might be helpful to you. 

I personally recommend Nature's Miracle Intense Defense Clumping Clay litter. Below is the link to my review:

http://www.thecatsite.com/products/natures-miracle-intense-defense-clumping-litter

Others on this site also recommend this, which i might actually try based on reviews:

http://www.thecatsite.com/products/precious-cat-ultra-premium-clumping-cat-litter

i know for certain that the Nature's Miracle Litter is unscented, although it's not mentioned on the packaging.

Just buy more of your old litter and dump the box with the Fresh Step.  You can donate the rest of the Fresh Step to a rescue or keep it in your trunk for the next ice storm.  Actually, some stores like Petco and Petsmart will take back any purchase you don't like if you return it.