if your candy was slime it means you need more sugar, and/or a smaller potatoe. its trial and error, but tastes better with less sugar and therefore a smaller potatoe.
how large was your potatoe? thats most likely the issue, all you need to do is slowly add more powdered sugar until its at a good consistancy! the more sugar you use, the more candy you will have n the end!
Thanks for sharing this with us!