don't reload/refresh Layer and CATextLayer (iphone)

Question

I have layer and CATextLayer. I have code, e.g:

 CATextLayer *TextLayer = [CATextLayer layer];
        TextLayer.bounds = CGRectMake(0.0f, 0.0f, 245.0f, 290.0f);
        TextLayer.string = randomText;
        CTFontCreateWithName((CFStringRef)@"HelveticaNeue-Light", 0.0, NULL);
        TextLayer.backgroundColor = [UIColor blackColor].CGColor;
        TextLayer.position = CGPointMake(162.0, 250.0f);
        TextLayer.wrapped = YES;
        TextLayer.fontSize = 20;
        [self.view.layer addSublayer:TextLayer];

How can I reload/refresh or clear layer before add randomText? At the moment textRandom join to before add text (imposition of existing texts on each other) and I don't see anything.

Thanks for help!