Change your preferences here.
Causes sandstorm weather upon entering the battlefield. Instead of lasting 5 turns, it lasts the entire match, unless another weather is activated. If two weather inducers are sent out at the same time, the slower of the two will have their weather set up over the faster one. If sandstorm weather was already induced via Sandstorm, sending out a Pokemon with Sand Stream will make sandstorm indefinite. Sand Stream will immediately activate whenever the ability is acquired, such as through Skill Swap or Role Play.
Sand Stream is one of the best abilities available in competitive battling. Since it summons permanent sandstorm, it allows powerful attackers such as Landorus to truly shine, and was part of the reason for Excadrill's banning. It also boosts the Special Defense of Rock-type Pokemon such as Tyranitar, making them extremely bulky on the special side. Sand Stream is also fairly useful to break opposing Focus Sashes. Even then, Sand Stream can backfire on its user, since the very same abusers can often use their opponent's sandstorm to start wrecking. Since weather cannot stack up, Sand Stream can also be used to remove permanent rain or sunshine, both of which can cause troubles if not handled correctly. It is fairly useful to stop opposing weather abusers. Still, when using a Sand Stream Pokemon, one should always consider using teammates who are not hindered by sandstorm, since it can lead to defeat quite quickly otherwise.
Found in Dream World