All i am saying is that it works!!! it takes like 5 days though, i am doing it on some parts right now and after a day there is a noticable difference. on a tank empty it everyday if it is really rusty to get the debri out then put the same vinigar and salt back in and maybe on day 3 put new salt and vinigar back in and give it a cpl more days i have never done it on a tank myself but there is a thread or reply somewhere where they did and it worked good they have day 1-5 pics too but they used something to clean the vinigaar and salt resisdue out after and i cant remember what it was