Indian stone stain removal - ..possibly caused by granular lawn feed

[jonathanlatham]

I would like some advice on removing small stains on fairly recently laid unsealed indian stone, possibly caused by professional controlled release lawn fertiliser. To my knowledge the fertiliser didn't contain iron, although I am wondering if that information is accurate. The actual fertiliser supplier is telling me it could be the salt in the fertiliser granules that's ereoded the stone, however a supplier of indian stone tells me it wouldn't erode.
So the actual cause is a grey area which is making it difficult for me to decide on how to proceed. I've tried the hosepipe without success so I'm now hoping if you can advise on pressure washing or chemical treatments please.

I'm having trouble trying to upload an image to this forum. Any ideas?

[r896neo]

Iron is usually obvious because it stains rust coloured? I'd be very surprised if anything else in a weed and feed would stain??

Whilst they can be toward the acidic end of the pH scale they aren;t that severe.

What specific product was the turf treated with?

[RAPressureWashing]

OP,
Can you post a photo of how bad the staining is, as we have had to clean up loads of this type of staining after "lawns people" have messed peoples patios up.

[Forestboy1978]

I find that soapy water and a wire brush in circular motions and getting a bit of a sweat on gets rid of the get riddable!

If that doesn't work you might be screwed!

[Pablo]

feed and weeds all contain ferous sulphate which is what causes the rust marks on paving. Lithofin do a rust removes you've no chance of removing it with elbow grease because the stain is not superficial.

[RAPressureWashing]

Update,
I have had contact with the OP and have given him advice on how to resolve this.