self.children count doesn't give correct number - ios

Question

I have this method that is supposed to loop through my nodes and check how many tubes I have in my parent, and if it is less than 6, I should add more. The first 6 work, but after they are removed by the remove action [self.children count] still reports that they're are 6 tubes still there. It logs "Tube Amount: 6/6" even though on screen the node count is at 0. I need an accurate way to see how many nodes I have. here is my code:
-(void) checkTubes {
int amt = 0;
SKSpriteNode *last;
for(SKSpriteNode *node in self.children)
if(node.size.height > 100) {
last = node;
amt++;
}
NSLog(#"Tube Amount: %i/%i", amt, [self.children count]);
if(amt < 6) {
for(SKSpriteNode *node in self.children)
if(node.size.height > 100)
last = node;
SKSpriteNode *tube1 = [SKSpriteNode spriteNodeWithImageNamed:#"tube"];
SKSpriteNode *tube2 = [SKSpriteNode spriteNodeWithImageNamed:#"tube2"];
int x1 = 155;
int y1 = -100;
int x2 = x1;
int y2 = y1+tube1.size.height + 68;
if(last != (id)[NSNull null]) {
x1 = last.position.x + x1;
x2 = x1;
}
tube1.position = CGPointMake(x1, y1);
tube2.position = CGPointMake(x2, y2);
[self addChild:tube1];
[self addChild:tube2];
SKAction *actionMove1 = [SKAction moveTo: CGPointMake(tube1.position.x - 1600, tube1.position.y) duration: 15.55f];
SKAction *actionMove2 = [SKAction moveTo: CGPointMake(tube2.position.x - 1600, tube2.position.y) duration: 15.55f];
SKAction *actionMoveDone = [SKAction removeFromParent];
[tube1 runAction:[SKAction sequence:#[actionMove1, actionMoveDone]]];
[tube2 runAction:[SKAction sequence:#[actionMove2, actionMoveDone]]];
}
}

Answer 1

You can not use the same action for multiple nodes without copying the action. This might fix it:
SKAction *actionMoveDone = [SKAction removeFromParent];
[tube1 runAction:[SKAction sequence:#[actionMove1, actionMoveDone]]];
// 2nd and any following use of the same action must be a 'copy'
[tube2 runAction:[SKAction sequence:#[actionMove2, [actionMoveDone copy]]]];