I am skeptical of posting in this thread based on the negativity and lack of tactfulness of some of the comments. However, there are some unwarranted attacks here that need to be addressed.
First let me start by saying thank you to all who have defended Seachem and our products in this thread. We depend on people like you in times where these types of threads are not brought to out attention. I would also like to point out that the two responses received from our product support representative were from the same individual so I am not sure where the supposed discrepancy lies. At any rate, the individual who answered is an adult (not a high schooler) who actually has a Bachelor's degree in Biology, as do all of the members of our technical support team. I do apologize if the answer was not quite as detailed as one would have liked, but perhaps the question should have a been a little bit more detailed? At any rate, Prime is a reducing agent as are MANY other products that are available in this hobby. Prime has been around for a few decades, so we do have much experience with using and dosing this product. We do know that at 5X the recommended dosage, all aquariums will not have any adverse effects. A reducing agent has the capability of reducing a lot of different elements in the aquarium. Prime has a preference for ammonia, nitrite, nitrate, chlorine, chloramine, heavy metals, etc. Essentially, if none of these things are present in the water, the reducing agent will bind to other things and reduce them instead. Oxygen is one of these things I am referring to. Likely, an individual will not be overdosing Prime unless that have some of the above mentioned elements available, correct? The amount that one person can dose is going to ultimately be dependent upon their water parameters. We all know how circumstantial this hobby is

Something may work for one person, but not the next. Based on our testing, we are confident that our dosage can be safely increased up to 5X the recommended dosage amount without killing anything. If we were not confident in this, we would certainly not put this in writing. Here is a link to one of the articles available on our website where we do mention the whole overdosing aspect if you are interested:
http://www.seachem.com/Library/SeaGrams/Ammonia_Management.pdf
Prime does break down and after about 24 hours it dissipates from the water so there is no chance of build up. I am not sure how far I can go into this based on proprietary grounds, but I will definitely ask my Reasearch Director on Monday if there is any additional information that I can provide without revealing trade secrets. It is now Friday at 6:00pm and I am going home. I will be glad to answer any specific questions you have about any of our products on Monday! Hope everyone has a great weekend!