Not actually done the titration bit of this method, though I have been using vinegar in the first wash for some time. I need to get some stronger acid, hydrochloric is out for me as I have 316 stainless fittings, so would be looking at sulphuric or phosphoric, both being a similar price volume wise. What's the thoughts on phosphoric? Which would be best for use with stainless?
Also looking at the indicator for the test. Bromthymol blue looks to be best due to the colour change point, next being phenol red. Any ideas where these can be acquired?