I was trying to make a longer lasting Xtol equivalent (the standard formula works quite well).
I split it in two solutions - dev and alkali, and added (a lot) of boric acid to the dev so it would become slightly acid.

So far, so good.

In the same week;
- did a black leader test - OK
- did a short strip test - OK
- shot half a 35mm roll - Ok
- shot the rest of the roll - almost clear...:evil:

Recheked with a leader test - clear.

My conclusion - there is somenting (impurities) in boric acid that kills ascorbic acid.

Jorge O