Easy way to get rid of rust marks?


Bronze Supporter
Jan 8, 2019
Hi all

We had a new pergola installed adjacent to our fibreglass pool. Seems a bunch if metal shavings, (likely from when they were installing the metal roof) have made their way into the pool.

I now have a bunch of small rust marks. It's not the end of the world, but ideally I'd like to remove them.

Ive tried the Vitamin C thing, but it seems like it will take too long. Is there a safe, whole pool treatment that anyone has used with success?

Is there a trick to the vitamin C thing? I grabbed a Vitamin C tablet and rubbed on a rust mark and after 5 mins of solid rubbing it had faded a little. Am I doing something wrong?

Ideally a whole pool treatment would be fantastic as long as it's safe for a 2 year old fibreglass pool

Cheers Luke


Bronze Supporter
Dec 13, 2018
Orlando, FL
I have a gunite pool, so please take that in mind with my advice. I am not sure if it will damage a fiberglass pool.

I have done vitamin C thing. Just leave it sit there for about 5 mins.then scrub with the tablet.

Also, I have done this, which I didn’t think would work, but it did. Get a long enough piece of 1/2” PVC pipe and a funnel that fits. Place the end of the pipe on the mark Pour some muriatic acid in the pipe. Believe it or not, the acid flows down the pipe to the spot and cleans it up. A little brushing finishes it up.

One more tip I have not tried is the dry acid in a sock. Place it on the spot and let sit. You probably have to monitor this since you don’t want the acid eating away too much.

Good luck.

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
If the stains are actually from iron metal shavings, then Vitamin C should do the trick. The fact they seem resistant is interesting. But for those who do have wide-spread iron staining, they may follow the Ascorbic Treatment to rid Pool of metal stains instructions. No big trick to the Vitamin C thing really. Some rub a tablet directly on a mark, while others may place in a thin sock or nylon and let it sit for a few.

Improvement using dry acid generally confirms copper, so I wouldn't think that would apply. And improvement with a chlorine tablet rubbed gently for a short time would indicate organic. Hopefully neither of those would apply to your situation.