When to mix new Diafine?

[snark]

I started using diafine about six months ago. Aside from watching for indications that it is no longer working, is there a way to know when to dump it and mix new?

 

[compur]

You don't really need to dump it -- just replenish it.
See data sheet:
https://www.digitaltruth.com/products/acufine_tech/acufine.pdf

 

[snark]

Huh. Okay, just top up the bottles with equal amounts when the A solution gets so low it will no longer cover the film and that will suffice to keep it replenished. I had read the data sheet but thought there must to be more to it than that. Hard to ignore shibboleths that have been observed for fifty years. Thanx.