iOS: How to remove object from memory with ARC enabled?

I am developing an iOS app with the iOS 5 SDK, Automatic Reference Counting is enabled. But I have a specific object that is being created in large numbers and must be released after a second because otherwise the device will become very slow. It looks like they are not released, as the device is very slow. Is there a way to manually release an object when ARC is enabled?

EDIT: My code, this is called 200 times a second to generate sparkles. They fade out after 0.8 seconds so they are useless after then.

    int xanimationdiff = arc4random() % 30;
    int yanimationdiff = arc4random() % 30;
    if (arc4random()%2 == 0) {
        xanimationdiff = xanimationdiff * -1;
    }
    if (arc4random()%2 == 0) {
        yanimationdiff = yanimationdiff * -1;
    }

    Sparkle *newSparkle = [[Sparkle alloc] initWithFrame:CGRectMake(20 + arc4random() % 280, 20, 10, 10)];
    //[newSparkle setTransform:CGAffineTransformMakeRotation(arc4random() * (M_PI * 360 / 180))]; //Rotatie instellen (was niet mooi, net sneeuw)
    [self.view addSubview:newSparkle];
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.8];
    [newSparkle setFrame:CGRectMake(newSparkle.frame.origin.x - xanimationdiff, newSparkle.frame.origin.y - yanimationdiff, newSparkle.frame.size.width, newSparkle.frame.size.height)];
    newSparkle.alpha = 0;
    [UIView commitAnimations];

The sparkle object code:

#import "Sparkle.h"

@implementation Sparkle

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:@"sparkle.png"]]];
    }
    return self;
}

@end