stainless hlt problem

[danb]

Just dried the hlt and there's a mark that seems almost burned. It wasn't there before and the only difference is I used AMS today. The mark is in the direction I squirted the AMS but the hlt had water in. I stirred the water about 10 minutes after adding. Only 11ml of AMS was used too so not huge amounts.
Is my pot nackerd?
Thanks

[danb]

[chastuck]

Probably not. Might need re-passivation. Get some Bar Keepers Friend (Waitrose sell it), make a stiff paste and rub the area with a coarse damp cloth. Leave it on for 10 mins and rinse off. Might need several applications.

[vacant]

I spilt a bit of CRS on the stainless kitchen drainer. Looks much the same and hasn't changed over the years.

[danb]

How do I prevent then mate? Stir as soon as added so its not so concentrated in one spot and does it make a difference if I've started heating before adding?
Cheers

[vacant]

I reckon as it's tarnish rather than rust there's no practical reason to prevent it. I tip my acid into a shot glass so I can use a plastic syringe to measure out. Then I squirt the syringe into the middle of the filled kettle. My boiler is plastic so I don't care if it ain't shiny.

[chastuck]

I always run my tap water into a 100L plastic cold liquor tank first. I had my acids to this before pumping into HLT.

[danb]

I think its because I didn't stir straight away, will see what happens next brewday.

[barneey]

If its a CRS stain its there to stay

[danb]

Is it that powerful even in some much water? Wow best make sure I don't spill it then. I've just tested the AMS I have. I used grahams water calculator yesterday but didn't retest once added. I've just done a 1l test. Which was 79.5 as caco3 to start with then the calculator said to add 0.3ml and when retested came out at 45 caco3 is this right?
Thanks