I am using Gainer formula but haven't done any real test to comment on. It's really easy to make an usable formula based on some simple calculation and cut and try, but it's much harder to seriously test and eveluate the developer's performance with each film I use.(posted 8201 days ago)Regarding the stock solution, I put sulfite together with developing agents, not with the base. Even if I keep metol/phenidone solution acidic, without sufficient sulfite, it seems much quicker to die. I remember metol/hydroquinone/boric acid/metabisulfite solution died hopelessly quickly even though the bottle was totally filled with the solution. Same with phenidone. For this reason I would not keep Gainer developer without sulfite, and mix fresh each time as he recommends.