The most dramatic changing juice I had was a pretty light yellow juice and it turned almost brown, it was one of the most expensive juices around too. I am not sure what you mean by tapered drip tip, where is it tapered and why? Sorry if that is a dumb question, I just cant imagine what you mean. Also could you send me the measurements for the poly tube, I cant find my calipers and am having issues using a tape measure.I find that the juice changes only on the darker juices. I have not had any tubes crack yet. I buy my own through mcmaster carr. I have never had a leak either. I take care if the orings and change them at the first sign of wear. I also use a tapered drip tip when running the carto through the caps. This stops the damaged to the inside oring
EDIT: Nevermind, I figured it out, tapered tip to insert the carto, sorry, just woke up.