They both seems to be the same.. but not sure which one is better in Pool is all balanced but brown stains. Use the step stuff works well or even the vit c tabs.. metal or even some copper is always going to be in pool. There is no way to totally remove it. The only way is to use something like this to remove it. Anyone willing to share? I have a vinyl 23000 gal pool.. liner about 4 yrs old, sand filter. Use the vit c and it worked well.. but cannot keep doing that. Use Magenta stuff along with step stuff works about 80% but need to find a way for maintaining.