By adding plants, and depending on the amount of plants, you can eliminate the need for a traditional cycle. The plants gorw using the ammonium for of ammonia as food. This way the bacteria doesn't have a chance to get at in and spike. So if you have a lot of plants in your tank, then you will only have to wait a very short amount of time before you can put fish in, say a day or two, maximum. Also I would not use mollies as they prefer a brackish set-up, and won't do as well in fresh water. Aswell salt is a no, no with live plants, they cannot tolerate it. If you really want to add fish, try something like guppies or platies.