How to remove iron sulphate stains from concrete slabs?

JohnSwift10

Is there a non expensive way to remove iron sulphate stains from concrete paving slabs?

grumpy_codger

According to Google, reportedly rust removers can do this.

JohnSwift10

https://forums.moneysavingexpert.com/discussion/comment/82061641#Comment_82061641

Have you seen the price of them?

I was looking for something homemade and cheaper.

FreeBear

I was looking for something homemade and cheaper.

Oxalic acid used to be my go-to when you buy it from places like Boots. I see several sources of 5% or 10% solutions on ebay for £8 to £25 depending on quantity & strength.

Rhubarb leaves are also a good source of oxalic acid, all be it at 0.5% to 1% by weight. If you decide to go this route, don't use pans from the kitchen. Oxalic acid is poisonous and can do a lot of damage to your kidneys. So grab a pan from a local charity shop and dispose of it at the local tip when done.