Cleaning a used tank

Question
I just acquired 2 glass tanks, 1 55gl and a 20 gl. Both tanks have pretty bad calcification around the top and I am trying to clean this off.  I am using a cleaner I got from a Pet store and I understand that I can't use a commercial de-scaler because that would "stain" the glass and harm the fish.  I've used vinegar to clean coffee pots would that work in the glass tanks?  I do plan on rinsing out both tanks thoroughly after I do anything.

Thanks - Don

Answer
Hi Don,
Thank you for your question. I think vinegar would be okay. After the vinegar, wash it out with shower gel or dish soap and water, then rinse thoroughly with a hose.
I want to warn you that the tank is the least expensive component of this hobby.
For overall info., here is my page for easy holistic aquarium care:
http://steamboats.com/aquarium.html
Write back if you want to discuss further.
Nori