although I don't have problems with hard tap water at home I tried to add it to my favourite developer in concentration of 5 g/l of working solution. Well, the negative came out underdeveloped, so I researched more and came to a conclusion, that EDTA and EDTA-2Na are mildly acidic. As I'm not a chemist in any way and have a very bad knowledge of the pH stuff & so on (and I don't have means of measuring pH in any way)... well, suppose I want to add EDTA-2Na into a bucket of water and since it is acidic I will put there, say, NaOH to neutralize it - or is this a completely wrong idea? EDTA-2Na can be written as C10H14N2Na2O8 . 2H2O so the reaction can be written in a this way (1 mol of both substances) C10H14N2Na2O8 + NaOH + (n)H2O --> C10H13N2Na3O8 + (n+1)H2O C10H13N2Na3O8 is EDTA-3Na - a trisodium salt which should be pH neutral in solution (depending on its chemical purity I suppose). can anybody here who understands chemistry better than me help me please?