I've been thinking about Oxalic Acid recently. In Arentz's book he suggest a Ferric Oxalate A recipe of 15g Ferric Oxalate + 1g of Oxalic Acid + 55ml water; and there's a footnote that says that adding more Oxalic Acid increases speed. I'm thinking about doing some experiments by varying the Oxalic Acid in the FO mix. But before I do that I thought it would be useful to ask about this here. My question is: other than a change in speed, what else does varying the amount of Oxalic Acid do? Is there a tone change, does it effect quality, or is there anything else that I should look out for? For reference, my developer is Potassium Oxalate + Potassium Dichromate for contrast control. Thanks in advance. Ian.