PC NetwoRx Pure Ascorbic Acid (Vitamin C) Powder (3 Pound)

Wonderful product! Stains are removed easily with this. If I need the stain removed quick I pour some in a microfiber cloth and tie it. I then wipe the fiberglass pool wall where the stain is and it comes off with a few swipes. It takes off the line around the pool very nicely!

This helps with rust / metal stains on your pool finish from metal ions that are present in well water, such as iron / sulfur. I am continually surprised at how other companies (Pinch-a-Penny / Leslie's) can get away with overcharging you for something as simple as this. Leslie's pool supply sells a 2lb containers for $50. $50! - why? For overpriced vitamin C? This is how you get the best results. Step 1 - use a chlorine neutralizer, reduce your chlorine (also can get on Amazon at a great price) down to 1-0 ppm. Step 2 - pour about 1lb of the Ascorbic Acid powder per 10K pool water around perimeter run filter over night, you should wake up to a stain free pool. Step 3 - so stains do not return you need to use a sequestering agent to trap the metal ions or the stains will return. Use Metal Free (also can get on Amazon at a great price) NOTE: these products (sequestering agent) DO NOT REMOVE metal, they bind the metal ions so they don't release on your finish. You need to provide weekly or monthly doses of the sequestering agent, (Metal Free) to control the metal. (you want a sequestering agent that does not have phosphates) Another note: I have seen other products that claim to actually REMOVE the metal - I'll update this post once I know if they work. Hope you find this helpful.

Before and after pic posted- stuff works almost instantly for your pool and is less than half price of the pool branded items. I was hesitant because the reviews mentioned well water stains but I have city water and worked as hoped. Buy this stuff if you have pool stains, just make sure that you have low chlorine levels before putting it in. I didn't add this to the skimmer, just sprinkled around edges of pool. Hope this helps someone else!

Have used it and it definitely works. It took every spot of rust off the pool marcite. Will always have on hand incase I need again.

I purchased this product before from the company, now it's on Amazon. My pool is white F'glass 16k gallons.I add a small amount, 12 or so ounces, around the perimeter of the pool. That's all ! 20 minutes later and it'sall clean. Steps included. I wait for the pump to go off and the water to be still. Also works great in the coffeemaker.I think the culprit is the HTH tabs.

This product is amazing for removing stains from a fiberglass pool!! Just lower the chlorine to 0 then spread the powder around the sides approximately 1lb per 16000 gallons. The stains start to disappear immediately. Reapply in a couple of hours if any stains remain. If you have any residual staining at the water line put some on a hand towel wet wipe incredible!! I use Metal Out stain and mineral inhibitor first to remove the metals from the water before using this product. Also with fiberglass pools alway keep the PH at the minimal like 7.2 that helps to prevent staining. High PH produces brown/copper looking stains.

This worked great to remove my metal stains on the pool liner. I put half the bag in my 18,000 salt water pool and within an hour the stains I've been fighting for 2 months cleared up completely. I did get my Chlorine down to <1 ppm before adding the acid. I had been working with a pool shop but since they couldn't find any metal I my pool sample they kept selling me different products. The one product they sold me for metal removal did not work. So I went online and followed the advice To try rubbing vitamin c tablets in a sock onto the stain and it worked so I ordered the ascorbic acid .

This product is amazing. I sprinkled it around the edge of the fiberglass and while sprinkling I looked back and stain was gone. It was instant. Will definitely order again to keep on hand. Spent several hundred having the pool muriatic acid cleaned to remove the stain. Wow instantly gone.