Natural Chemistry Extra Strength Stain Free, 1.75 lb, Single, Removes Metal Stains from Pool Liners & Finishes, Compatible with All Sanitizing Systems

This is truly a great product. Works wonders on the worst stains in our pool. I absolutely love this stuff. Removes yellowing stains from the stairs as well as other areas of the pool. Works quickly and leaves the pool beautiful. I recommend this product for sure.

I was skeptical of this, but it actually saved me a good $1000 from having a drain and acid wash done. I honestly didn’t know how to test ph or chlorine and just took a chance by pouring it in. Got rid of dark stains on white plaster that can happen when the chemistry is off from time to time. Returned to a white color. Couldn’t be happier.

This worked great to remove rust stains! I tried physically scrubbing the stain with zero change. In the first I tire, you can see two rust stains. There’s another one to the side. So I put this product in a tube sock. Added a rock. Tied off the sock. Dropped it on top of the first stain, rock side up, shown in the picture. 5 minutes later it was almost all gone. Repeated for all three spots for 10-30 minutes and they’re all completely gone!! I didn’t have to use so much product and we can get the pool opened sooner than treating the 27k gallon pool. I did sprinkle one can around the edges and the sides are all clearing from slight discoloration. The pool looks perfect! I’m super pleased! Highly recommend!

Was worried about what people said of cloudy water after using this. That did not happen. My liner looked awful. It was patchy yellow brown on at least half of the floor. Thought maybe it was yellow mustard. Bought chemicals for this. Did more searching came upon staining from minerals. Decided to do this first. Am I glad. Followed other review sprinkling it in and then recirculating for about two hours. Shut off pump over night. The next morning it was back to being blue. I was never so happy! Turned on the filter and brushed the bottom. Then poured in Metal Out according to the bottle and let the filter run the day and night. Everything tested fine except the chlorine of course. Did add some algecide. Several hours later some chlorine. I am adding it in gradually. Not going to shock for at least a week just to be safe. Three days in and the pool is super blue and crystal clear. Running the pump on my regular schedule and off at night. I never had this issue in the thirty years we had the pool. Could not say enough how great this product is. Don’t be scared to try it.

It helps with the brown stains in the pool but I had to use for bottle. It did not help with black spots.

AMAZING!! Saved me from a heart attack. I had put a POOL rx in my skimmer on a Sunday took a pool sample to the store on Tuesday and it showed no chlorine. I sprinkled a bag of shock in 2 places in my pool within 10 minutes a had 2 HUGE black spots on the bottom of my pool at least 6'x8'! I immediately put in mineral out it did nothing. I had some of the stain free left over from years ago I had my husband put on a mask and go under to right above the stain and sprinkle it on within 5 minutes the stain began to lift within 2 hours it was completely gone! I just purchased to have on hand in case this ever happens again do not want to be without this product!

Took the stains right out with one application.

I owned a pool service company for 4 years. This stuff always saved me with my customers, and keeps my pool crystal clear, here in NC the water (city) has a good bit of iron in it that stains all pools. This stuff (ascorbic acid) makes the iron release. Combine this with a C-Ulator pack and it will get the stains out until the next time you have to “top up” your pool with the hose.

used for removing metal staining on the whole of a pre-formed pool. excellent.