Stains no quite coming out with Vitamin C, maybe not enought POP?

[mbar]

Keep the ph low, add some more ascorbic acid - try to add it where the stains are most prevelent - You should be ok with the sequesterer, but if yo have more add another half bottle, more is better than not enough, and it depends on how much staining you had - turn the filter to cirulate for about 2 hours, then back to filter. If you have extra ascorbic acid, it will only filter out - so don't worry about that. Sometimes it's hard to have patience - but you should see all of the stain go away with the intial dose of ascorbic acid, if it didn't that means that there wasn't enough of aa or sequesterer. The only time it's better to wait is if the stain is new - then you take the ph down add sequestering agent and wait to see if they disappear. Welcome to the forum, feel free to ask any other questions you may have.